Aristotle (384–322 B.C.E.) numbers among the greatestphilosophers of all time. Judged solely in terms of his philosophicalinfluence, only Plato is his peer: Aristotle’s works shaped centuriesof philosophy from Late Antiquity through the Renaissance, and eventoday continue to be studied with keen, non-antiquarian interest. Aprodigious researcher and writer, Aristotle left a great body of work,perhaps numbering as many as two-hundred treatises, from whichapproximately thirty-one survive.^[1] His extant writings span a wide range ofdisciplines, from logic, metaphysics and philosophy of mind, throughethics, political theory, aesthetics and rhetoric, and into suchprimarily non-philosophical fields as empirical biology, where heexcelled at detailed plant and animal observation and description. In all these areas, Aristotle’s theories have providedillumination, met with resistance, sparked debate, and generallystimulated the sustained interest of an abiding readership.

Because of its wide range and its remoteness in time,Aristotle’s philosophy defies easy encapsulation. The longhistory of interpretation and appropriation of Aristotelian texts andthemes—spanning over two millennia and comprising philosophersworking within a variety of religious and secular traditions—hasrendered even basic points of interpretation controversial. Theset of entries on Aristotle in this site addresses this situation byproceeding in three tiers. First, the present, general entryoffers a brief account of Aristotle’s life and characterizes hiscentral philosophical commitments, highlighting his most distinctivemethods and most influential achievements.^[2] Second areGeneral Topics, which offer detailed introductionsto the main areas of Aristotle’s philosophical activity. Finally,there followSpecial Topics, which investigate in greaterdetail more narrowly focused issues, especially those of centralconcern in recent Aristotelian scholarship.

• 1. Aristotle’s Life
• 2. The Aristotelian Corpus: Character and Primary Divisions
• 3.Phainomena and the Endoxic Method
• 4. Logic, Science, and Dialectic
  • 4.1 Logic
  • 4.2 Science
  • 4.3 Dialectic
• 5. Essentialism and Homonymy
• 6. Category Theory
• 7. The Four Causal Account of Explanatory Adequacy
• 8. Hylomorphism
• 9. Aristotelian Teleology
• 10. Substance
• 11. Living Beings
• 12. Happiness and Political Association
• 13. Rhetoric and the Arts
• 14. Aristotle’s Legacy
• Bibliography
  • A. Translations
  • B. Translations with Commentaries
  • C. General Works
  • D. Bibliography of Works Cited
• Academic Tools
• Other Internet Resources
• Related Entries

1. Aristotle’s Life

Born in 384 B.C.E. in the Macedonian region of northeastern Greece inthe small city of Stagira (whence the moniker ‘theStagirite’, which one still occasionally encounters inAristotelian scholarship), Aristotle was sent to Athens at about theage of seventeen to study in Plato’s Academy, then a pre-eminentplace of learning in the Greek world. Once in Athens, Aristotleremained associated with the Academy until Plato’s death in 347,at which time he left for Assos, in Asia Minor, on the northwest coastof present-day Turkey. There he continued the philosophical activityhe had begun in the Academy, but in all likelihood also began toexpand his researches into marine biology. He remained at Assos forapproximately three years, when, evidently upon the death of his hostHermeias, a friend and former Academic who had been the ruler ofAssos, Aristotle moved to the nearby coastal island of Lesbos. Therehe continued his philosophical and empirical researches for anadditional two years, working in conjunction with Theophrastus, anative of Lesbos who was also reported in antiquity to have beenassociated with Plato’s Academy. While in Lesbos, Aristotlemarried Pythias, the niece of Hermeias, with whom he had a daughter,also named Pythias.

In 343, upon the request of Philip, the king of Macedon, Aristotleleft Lesbos for Pella, the Macedonian capital, in order to tutor theking’s thirteen-year-old son, Alexander—the boy who waseventually to become Alexander the Great. Although speculationconcerning Aristotle’s influence upon the developing Alexander hasproven irresistible to historians, in fact little concrete is knownabout their interaction. On the balance, it seems reasonable toconclude that some tuition took place, but that it lasted only two orthree years, when Alexander was aged from thirteen to fifteen. Byfifteen, Alexander was apparently already serving as a deputy militarycommander for his father, a circumstance undermining, ifinconclusively, the judgment of those historians who conjecture alonger period of tuition. Be that as it may, some suppose that theirassociation lasted as long as eight years.

It is difficult to rule out that possibility decisively, since littleis known about the period of Aristotle’s life from341–335. He evidently remained a further five years in Stagiraor Macedon before returning to Athens for the second and final time,in 335. In Athens, Aristotle set up his own school in a publicexercise area dedicated to the god Apollo Lykeios, whence its name,theLyceum. Those affiliated with Aristotle’s schoollater came to be calledPeripatetics, probably because of theexistence of an ambulatory (peripatos) on the school’sproperty adjacent to the exercise ground. Members of the Lyceumconducted research into a wide range of subjects, all of which were ofinterest to Aristotle himself: botany, biology, logic, music,mathematics, astronomy, medicine, cosmology, physics, the history ofphilosophy, metaphysics, psychology, ethics, theology, rhetoric,political history, government and political theory, and the arts. Inall these areas, the Lyceum collected manuscripts, thereby, accordingto some ancient accounts, assembling the first great library ofantiquity.

During this period, Aristotle’s wife, Pythias, died and hedeveloped a new relationship with Herpyllis, perhaps like him a nativeof Stagira, though her origins are disputed, as is the question of herexact relationship to Aristotle. Some suppose that she was merely hisslave; others infer from the provisions of Aristotle’s will thatshe was a freed woman and likely his wife at the time of hisdeath. In any event, they had children together, including a son,Nicomachus, named for Aristotle’s father and after whom hisNicomachean Ethics is presumably named.

After thirteen years in Athens, Aristotle once again found cause toretire from the city, in 323. Probably his departure wasoccasioned by a resurgence of the always-simmering anti-Macedoniansentiment in Athens, which was free to come to the boil after Alexandersuccumbed to disease in Babylon during that same year. Because ofhis connections to Macedon, Aristotle reasonably feared for his safetyand left Athens, remarking, as an oft-repeated ancient tale would tellit, that he saw no reason to permit Athens to sin twice againstphilosophy. He withdrew directly to Chalcis, on Euboea, an islandoff the Attic coast, and died there of natural causes the followingyear, in 322.^[3]

2. The Aristotelian Corpus: Character and Primary Divisions

Aristotle’s writings tend to present formidable difficulties tohis novice readers. To begin, he makes heavy use of unexplainedtechnical terminology, and his sentence structure can at times provefrustrating. Further, on occasion a chapter or even a fulltreatise coming down to us under his name appears haphazardlyorganized, if organized at all; indeed, in several cases, scholarsdispute whether a continuous treatise currently arranged under a singletitle was ever intended by Aristotle to be published in its presentform or was rather stitched together by some later editor employingwhatever principles of organization he deemed suitable.^[4] This helps explain whystudents who turn to Aristotle after first being introduced to thesupple and mellifluous prose on display in Plato’s dialoguesoften find the experience frustrating. Aristotle’s proserequires some acclimatization.

All the more puzzling, then, is Cicero’s observation that ifPlato’s prose was silver, Aristotle’s was a flowing riverof gold (Ac. Pr. 38.119, cf.Top. 1.3,Deor. 1.2.49). Cicero was arguably the greatest prose stylist ofLatin and was also without question an accomplished and fair-mindedcritic of the prose styles of others writing in both Latin andGreek. We must assume, then, that Cicero had before him works ofAristotle other than those we possess. In fact, we know thatAristotle wrote dialogues, presumably while still in the Academy, andin their few surviving remnants we are afforded a glimpse of the styleCicero describes. In most of what we possess, unfortunately, wefind work of a much less polished character. Rather,Aristotle’s extant works read like what they very probably are:lecture notes, drafts first written and then reworked, ongoing recordsof continuing investigations, and, generally speaking, in-housecompilations intended not for a general audience but for an innercircle of auditors. These are to be contrasted with the“exoteric” writings Aristotle sometimes mentions, his moregraceful compositions intended for a wider audience (Pol.1278b30;EE 1217b22, 1218b34). Unfortunately, then, weare left for the most part, though certainly not entirely, withunfinished works in progress rather than with finished and polishedproductions. Still, many of those who persist with Aristotle cometo appreciate the unembellished directness of his style.

More importantly, the unvarnished condition of Aristotle’ssurviving treatises does not hamper our ability to come to grips with theirphilosophical content. His thirty-one surviving works (that is,those contained in the “Corpus Aristotelicum” of ourmedieval manuscripts that are judged to be authentic) all containrecognizably Aristotelian doctrine; and most of these contain theseswhose basic purport is clear, even where matters of detail and nuanceare subject to exegetical controversy.

These works may be categorized in terms of the intuitiveorganizational principles preferred by Aristotle. He refers to thebranches of learning as “sciences”(epistêmai), best regarded as organized bodies oflearning completed for presentation rather than as ongoing records ofempirical researches. Moreover, again in his terminology,naturalsciences such as physics are but one branch oftheoreticalscience, which comprises both empirical and non-empiricalpursuits. He distinguishes theoretical science from more practicallyoriented studies, some of which concern human conduct and others ofwhich focus on the productive crafts. Thus, the Aristotelian sciencesdivide into three: (i) theoretical, (ii) practical, and (iii)productive. The principles of division are straightforward:theoretical science seeks knowledge for its own sake; practicalscience concerns conduct and goodness in action, both individual andsocietal; and productive science aims at the creation of beautiful oruseful objects (Top. 145a15–16;Phys. 192b8–12;DC 298a27–32,DA 403a27–b2;Met. 1025b25, 1026a18–19,1064a16–19, b1–3;EN 1139a26–28,1141b29–32).

(i) Thetheoretical sciences include prominently whatAristotle callsfirst philosophy, or metaphysics as we nowcall it, but alsomathematics, andphysics, ornatural philosophy. Physics studies the natural universe as awhole, and tends in Aristotle’s hands to concentrate onconceptual puzzles pertaining to nature rather than on empirical research;but it reaches further, so that it includes also a theory of causalexplanation and finally even a proof of an unmoved mover thought to bethe first and final cause of all motion. Many of the puzzles of primaryconcern to Aristotle have proven perennially attractive tophilosophers, mathematicians, and theoretically inclined naturalscientists. They include, as a small sample, Zeno’sparadoxes of motion, puzzles about time, the nature of place, anddifficulties encountered in thought about the infinite.

Natural philosophy also incorporates the special sciences, includingbiology, botany, and astronomical theory. Most contemporarycritics think that Aristotle treats psychology as a sub-branch ofnatural philosophy, because he regards the soul (psuchê)as the basic principle of life, including all animal and plantlife. In fact, however, the evidence for this conclusion isinconclusive at best. It is instructive to note that earlier periods ofAristotelian scholarship thought this controversial, so that, forinstance, even something as innocuous-sounding as the question of theproper home of psychology in Aristotle’s division of the sciencesignited a multi-decade debate in the Renaissance.^[5]

(ii)Practical sciences are less contentious, at least asregards their range. These deal with conduct and action, bothindividual and societal. Practical science thus contrasts withtheoretical science, which seeks knowledge for its own sake, and, lessobviously, with the productive sciences, which deal with the creationof products external to sciences themselves. Both politics andethics fall under this branch.

(iii) Finally, then, theproductive sciences are mainlycrafts aimed at the production of artefacts, or of human productionsmore broadly construed. The productive sciences include, amongothers, ship-building, agriculture, and medicine, but also the arts ofmusic, theatre, and dance. Another form of productive science isrhetoric, which treats the principles of speech-making appropriate tovarious forensic and persuasive settings, including centrally politicalassemblies.

Significantly, Aristotle’s tri-fold division of the sciencesmakes no mention of logic. Although he did not use the word‘logic’ in our sense of the term, Aristotle in factdeveloped the first formalized system of logic and validinference. In Aristotle’s framework—although he isnowhere explicit about this—logic belongs to no one science, butrather formulates the principles of correct argumentation suitable toall areas of inquiry in common. It systematizes the principleslicensing acceptable inference, and helps to highlight at an abstractlevel seductive patterns of incorrect inference to be avoided by anyonewith a primary interest in truth. So, alongside his moretechnical work in logic and logical theory, Aristotle investigatesinformal styles of argumentation and seeks to expose common patterns offallacious reasoning.

Aristotle’s investigations into logic and the forms ofargumentation make up part of the group of works coming down to us fromthe Middle Ages under the heading theOrganon(organon =tool in Greek). Although not socharacterized in these terms by Aristotle, the name is apt, so long asit is borne in mind that intellectual inquiry requires a broad range oftools. Thus, in addition to logic and argumentation (treatedprimarily in thePrior Analytics andTopics), theworks included in theOrganon deal with category theory, thedoctrine of propositions and terms, the structure of scientific theory,and to some extent the basic principles of epistemology.

When we slot Aristotle’s most important surviving authentic worksinto this scheme, we end up with the following basicdivisions of his major writings:

• Organon
  • Categories (Cat.)
  • De Interpretatione (DI) [On Interpretation]
  • Prior Analytics (APr)
  • Posterior Analytics (APo)
  • Topics (Top.)
  • Sophistical Refutations (SE)
• Theoretical Sciences
  • Physics (Phys.)
  • Generation and Corruption (Gen. et Corr.)
  • De Caelo (DC) [On the Heavens]
  • Metaphysics (Met.)
  • DeAnima (DA) [On the Soul]
  • Parva Naturalia (PN) [Brief Natural Treatises]
  • History of Animals (HA)
  • Parts of Animals (PA)
  • Movement of Animals (MA)
  • Meteorology (Meteor.)
  • Progression of Animals (IA)
  • Generation of Animals (GA)
• Practical Sciences
  • Nicomachean Ethics (EN)
  • Eudemian Ethics (EE)
  • Magna Moralia (MM) [Great Ethics]
  • Politics (Pol.)
• Productive Science
  • Rhetoric (Rhet.)
  • Poetics (Poet.)

The titles in this list are those in most common use today inEnglish-language scholarship, followed by standard abbreviations inparentheses. For no discernible reason, Latin titles arecustomarily employed in some cases, English in others. WhereLatin titles are in general use, English equivalents are given insquare brackets.

3.Phainomena and the Endoxic Method

Aristotle’s basic approach to philosophy is best grasped initially byway of contrast. Whereas Descartes seeks to place philosophy andscience on firm foundations by subjecting all knowledge claims to asearing methodological doubt, Aristotle begins with the convictionthat our perceptual and cognitive faculties are basically dependable,that they for the most part put us into direct contact with thefeatures and divisions of our world, and that we need not dally withsceptical postures before engaging in substantive philosophy.Accordingly, he proceeds in all areas of inquiry in the manner of amodern-day natural scientist, who takes it for granted that progressfollows the assiduous application of a well-trained mind and so, whenpresented with a problem, simply goes to work. When he goes to work,Aristotle begins by considering how the world appears, reflecting onthe puzzles those appearances throw up, and reviewing what has beensaid about those puzzles to date. These methods comprise his twinappeals tophainomena and the endoxic method.

These two methods reflect in different ways Aristotle’s deepestmotivations for doing philosophy in the first place. “Humanbeings began to do philosophy,” he says, “even as they donow, because of wonder, at first because they wondered about thestrange things right in front of them, and then later, advancinglittle by little, because they came to find greater thingspuzzling” (Met. 982b12). Human beings philosophize,according to Aristotle, because they find aspects of their experiencepuzzling. The sorts of puzzles we encounter in thinking about theuniverse and our place within it—aporiai, inAristotle’s terminology—tax our understanding and induce us tophilosophize.

According to Aristotle, it behooves us to begin philosophizing bylaying out thephainomena, theappearances, or, morefully,things appearing to be the case, and then alsocollecting theendoxa, the credible opinions handed downregarding matters we find puzzling. As a typical example, in apassage of hisNicomachean Ethics, Aristotle confronts apuzzle of human conduct, the fact that we are apparently sometimesakratic or weak-willed. When introducing this puzzle, Aristotle pausesto reflect upon a precept governing his approach to many areas of inquiry:

As in other cases, we must set out the appearances(phainomena) and run through all the puzzles regardingthem. In this way we must prove the credible opinions(endoxa) about these sorts of experiences—ideally, allthe credible opinions, but if not all, then most of them, those whichare the most important. For if the objections are answered andthe credible opinions remain, we shall have an adequate proof.(EN 1145b2–7)

Scholars dispute concerning the degree to which Aristotle regardshimself as beholden to the credible opinions (endoxa) herecounts and the basic appearances (phainomena) to which he appeals.^[6] Of course, since theendoxa will sometimes conflict with oneanother, often precisely because thephainomena generateaporiai, or puzzles, it is not always possible to respect themin their entirety. So, as a group they must be re-interpreted andsystematized, and, where that does not suffice, some must be rejectedoutright. It is in any case abundantly clear that Aristotle iswilling to abandon some or all of theendoxa andphainomena whenever science or philosophy demands that he doso (Met. 1073b36, 1074b6;PA 644b5;EN1145b2–30).

Still, his attitude towardsphainomena does betray apreference to conserve as many appearances as is practicable in a givendomain—not because the appearances are unassailably accurate, butrather because, as he supposes, appearances tend to track thetruth. We are outfitted with sense organs and powers ofmind so structured as to put us into contact with the world andthus to provide us with data regarding its basic constituents anddivisions. While our faculties are not infallible, neither arethey systematically deceptive or misdirecting. Sincephilosophy’s aim is truth and much of what appears to us provesupon analysis to be correct,phainomena provide both animpetus to philosophize and a check on some of its more extravagantimpulses.

Of course, it is not always clear what constitutes aphainomenon; still less is it clear whichphainomenonis to be respected in the face ofbona fidedisagreement. This is in part why Aristotle endorses his secondand related methodological precept, that we ought to beginphilosophical discussions by collecting the most stable and entrenchedopinions regarding the topic of inquiry handed down to us by ourpredecessors. Aristotle’s term for these privileged views,endoxa, is variously rendered as ‘reputableopinions’, ‘credible opinions’, ‘entrenchedbeliefs’, ‘credible beliefs’, or ‘commonbeliefs’. Each of these translations captures at least part ofwhat Aristotle intends with this word, but it is important toappreciate that it is a fairly technical term forhim. Anendoxon is the sort of opinion we spontaneouslyregard as reputable or worthy of respect, even if upon reflection wemay come to question its veracity. (Aristotle appropriates this termfrom ordinary Greek, in which anendoxos is a notable orhonourable man, a man of high repute whom we would spontaneouslyrespect—though we might, of course, upon closer inspection, findcause to criticize him.) As he explains his use of theterm,endoxa are widely shared opinions, often ultimatelyissuing from those we esteem most: ‘Endoxa are thoseopinions accepted by everyone, or by the majority, or by thewise—and among the wise, by all or most of them, or by those whoare the most notable and having the highest reputation’(Top. 100b21–23).Endoxa play a special rolein Aristotelian philosophy in part because they form a significantsub-class ofphainomena (EN 1154b3–8): because theyare the privileged opinions we find ourselves unreflectively endorsingand reaffirming after some reflection, they themselves come to qualifyas appearances to be preserved where possible.

For this reason, Aristotle’s method of beginning with theendoxa is more than a pious platitude to the effect that itbehooves us to mind our superiors. He does think this, as far asit goes, but he also maintains, more instructively, that we can be ledastray by the terms within which philosophical problems are bequeathedto us. Very often, the puzzles confronting us were given crispformulations by earlier thinkers and we find them puzzling preciselyfor that reason. Equally often, however, if we reflect upon theterms within which the puzzles are cast, we find a way forward; when aformulation of a puzzle betrays an untenable structuring assumption, asolution naturally commends itself. This is why in more abstractdomains of inquiry we are likely to find ourselves seeking guidancefrom our predecessors even as we call into question theirways of articulating the problems we are confronting.

Aristotle applies his method of running through thephainomena and collecting theendoxa widely, innearly every area of his philosophy. To take a typicalillustration, we find the method clearly deployed in his discussion oftime inPhysics iv 10–14. We begin with aphainomenon: we feel surethattime existsor at leastthat time passes. So much is, inescapably,how our world appears: we experience time as passing, asunidirectional, as unrecoverable when lost. Yet when we move tooffer an account of what time might be, we find ourselvesflummoxed. For guidance, we turn to what has been said about timeby those who have reflected upon its nature. It emerges directlythat both philosophers and natural scientists have raised problemsabout time.

As Aristotle sets them out, these problems take the form of puzzles,oraporiai, regarding whether and if so how time exists(Phys. 218a8–30). If we say that time is the totality of thepast, present and future, we immediately find someone objecting thattime exists but that the past and future do not. According to theobjector, only the present exists. If we retort then that time iswhatdid exist, what existsat present andwhatwill exist, then we notice first that our account isinsufficient: after all, there are many things which did, do, or willexist, but these are things that arein time and so not thesame as time itself. We further see that our account already threatenscircularity, since to say that somethingdid orwillexist seems only to say that it existed at an earliertime orwill come to exist at a latertime. Then again we findsomeone objecting to our account that even the notion of thepresent is troubling. After all, either the present isconstantly changing or it remains forever the same. If it remainsforever the same, then the current present is the same as the presentof 10,000 years ago; yet that is absurd. If it is constantly changing,then no two presents are the same, in which case a past present musthave come into and out of existence before the present present. When?Either it went out of existence even as it came into existence, whichseems odd to say the least, or it went out of existence at someinstant after it came into existence, in which case, again, twopresents must have existed at the same instant. Now, Aristotle doesnot endorse the claims set out in stating these sortsofaporiai; in fact, very often he cannot, becausesomeaporiai qualify asaporiai just because theycomprise individually plausible arguments generating incompatibleconclusions. They thus serve as springboards to deeper, moredemanding analysis.

In general, then, in setting suchaporiai, Aristotle does notmean to endorse any givenendoxon on one side or theother. Rather, he thinks that such considerations present crediblepuzzles, reflection upon which may steer us towards a defensibleunderstanding of the nature of time. In this way,aporiaibring into sharp relief the issues requiring attention if progress isto be made. Thus, by reflecting upon theaporiai regardingtime, we are led immediately to think about duration and divisibility,aboutquanta andcontinua, and about a variety ofcategorial questions. That is, if time exists, then what sort ofthing is it? Is it the sort of thing which exists absolutely andindependently? Or is it rather the sort of thing which, like asurface, depends upon other things for its existence? When webegin to address these sorts of questions, we also begin to ascertainthe sorts of assumptions at play in theendoxa coming down tous regarding the nature of time. Consequently, when wecollect theendoxa and survey them critically, we learnsomething about our quarry, in this case about the nature oftime—and crucially also something about the constellation ofconcepts which must be refined if we are to make genuine philosophicalprogress with respect to it. What holds in the case of time, Aristotle implies, holds generally. This is why hecharacteristically begins a philosophical inquiry by presenting thephainomena, collecting theendoxa, and runningthrough the puzzles to which they give rise.

4. Logic, Science, and Dialectic

Aristotle’s reliance onendoxa takes on a still greatersignificance given the role such opinions play indialectic,which he regards as an important form of non-scientificreasoning. Dialectic, like science(epistêmê), trades in logical inference; butscience requires premises of a sort beyond the scope of ordinarydialectical reasoning. Whereas science relies upon premises whichare necessary and known to be so, a dialectical discussion can proceedby relying onendoxa, and so can claim only to be as secure astheendoxa upon which it relies. This is not a problem,suggests Aristotle, since we often reason fruitfully and well incircumstances where we cannot claim to have attained scientificunderstanding. Minimally, however, allreasoning—whether scientific or dialectical—must respectthe canons of logic and inference.

4.1 Logic

Among the great achievements to which Aristotle can lay claim is thefirst systematic treatment of the principles of correct reasoning, thefirst logic. Although today we recognize many forms of logicbeyond Aristotle’s, it remains true that he not only developed atheory of deduction, now called syllogistic, but added to it a modalsyllogistic and went a long way towards proving some meta-theoremspertinent to these systems. Of course, philosophers beforeAristotle reasoned well or reasoned poorly, and the competent among themhad a secure working grasp of the principles of validity andsoundness in argumentation. No-one before Aristotle, however, developed asystematic treatment of the principles governing correct inference; andno-one before him attempted to codify the formal and syntacticprinciples at play in such inference. Aristotle somewhatuncharacteristically draws attention to this fact at the end of adiscussion of logic inference and fallacy:

Once you have surveyed our work, if it seems to you that our systemhas developed adequately in comparison with other treatments arisingfrom the tradition to date—bearing in mind how things were at thebeginning of our inquiry—it falls to you, our students, to beindulgent with respect to any omissions in our system, and to feel agreat debt of gratitude for the discoveries it contains (Soph.Ref. 184b2–8).

Even if we now regard it as commonplace that his logic is but afraction of the logic we know and use, Aristotle’s accomplishmentwas so encompassing that no less a figure than Kant, writing over twomillennia after the appearance of Aristotle’s treatises on logic,found it easy to offer an appropriately laudatory judgment: ‘Thatfrom the earliest times logic has traveled a secure course can be seenfrom the fact that since the time of Aristotle it has not had to go asingle step backwards…What is further remarkable about logic isthat until now it has also been unable to take a single step forward,and therefore seems to all appearance to be finished andcomplete’ (Critique of Pure Reason B vii).

In Aristotle’s logic, the basic ingredients of reasoning aregiven in terms ofinclusion andexclusion relations,of the sort graphically captured many years later by the device of Venndiagrams. He begins with the notion of a patently correct sort ofargument, one whose evident and unassailable acceptability inducesAristotle to refer to is as a ‘perfect deduction’(APr. 24b22–25). Generally, adeduction(sullogismon), according to Aristotle, is a valid oracceptable argument. More exactly, a deduction is ‘anargument in which when certain things are laid down something elsefollows of necessity in virtue of their being so’ (APr.24b18–20). His view of deductions is, then, akin to a notion ofvalidity, though there are some minor differences. Forexample, Aristotle maintains that irrelevant premises will ruin adeduction, whereas validity is indifferent to irrelevance or indeed tothe addition of premises of any kind to an already validargument. Moreover, Aristotle insists that deductions makeprogress, whereas every inference fromp top istrivially valid. Still, Aristotle’s general conception ofdeduction is sufficiently close to validity that we may pass intospeaking in terms of valid structures when characterizing hissyllogistic. In general, he contends that a deduction is the sortof argument whosestructure guarantees its validity,irrespective of the truth or falsity of its premises. This holdsintuitively for the following structure:

1. AllAs areBs.
2. AllBs areCs.
3. Hence, allAs areCs.

Accordingly, anything taking this form will be a deduction inAristotle’s sense. Let theAs,Bs, andCs be anything at all, andif indeed theAs areBs, andtheBsCs, thenof necessitytheAs will beCs. Thisparticular deduction isperfect because its validity needs noproof, and perhaps because it admits of no proof either: any proofwould seem to rely ultimately upon the intuitive validity of this sortof argument.

Aristotle seeks to exploit the intuitive validity of perfectdeductions in a surprisingly bold way, given the infancy of hissubject: he thinks he can establish principles of transformation interms of whichevery deduction (or, more precisely, everynon-modal deduction) can be translated into a perfect deduction. Hecontends that by using such transformations we can place alldeduction on a firm footing.

If we focus on just the simplest kinds of deduction,Aristotle’s procedure comes quickly into view. Theperfect deduction already presented is an instance of universalaffirmation: allAs areBs; allBsCs; and so, allAs areCs. Now, contendsAristotle, it is possible to run through all combinations of simplepremises and display their basic inferential structures and then torelate them back to this and similarly perfect deductions. Thus,if we vary thequantity of a proposition’s subject(universalall versus indeterminatesome) along withthequality or kind of the predication (positiveversusnegative), we arrive at all the possible combinationsof the most basic kind of arguments.

It turns out that some of these arguments are deductions, or validsyllogisms, and some are not. Those which are not admit ofcounterexamples, whereas those which are, of course, do not. There arecounterexamples to those, for instance, suffering from what came to becalled undistributed middle terms, e.g.: allAsareBs; someBs areCs; so, allAs areCs (all university students are literate;some literate people read poetry; so, all university students readpoetry). There is no counterexample to the perfect deduction in theform of a universal affirmation: if allAs areBs, and allBsCs, then there is no escaping the fact thatallAs areCs. So, if all the kinds of deductionspossible can be reduced to the intuitively valid sorts, then thevalidity of all can be vouchsafed.

To effect this sort of reduction, Aristotle relies upon a series ofmeta-theorems, some of which he proves and others of which he merelyreports (though it turns out that they do all indeed admit ofproofs). His principles aremeta-theorems in the sensethat no argument can run afoul of them and still qualify as a genuinededuction. They include such theorems as: (i) no deductioncontains two negative premises; (ii) a deduction with a negativeconclusion must have a negative premise; (iii) a deduction with auniversal conclusion requires two universal premises; and (iv) adeduction with a negative conclusion requires exactly one negativepremise. He does, in fact, offer proofs for the most significant of hismeta-theorems, so that we can be assured that all deductions in hissystem are valid, even when their validity is difficult to graspimmediately.

In developing and proving these meta-theorems of logic, Aristotlecharts territory left unexplored before him and unimproved for manycenturies after his death.

For a fuller account of Aristotle’s achievements in logic, see the entry onAristotle’s Logic.

4.2 Science

Aristotle approaches the study of logic not as an end in itself, butwith a view to its role in human inquiry and explanation. Logic is atool, he thinks, one making an important but incomplete contributionto science and dialectic. Its contribution is incomplete becausescience (epistêmê) employs arguments which aremore than mere deductions. A deduction is minimally a valid syllogism,and certainly science must employ arguments passing thisthreshold. Still, science needs more: a science proceedsbyorganizing the data in its domain into a series ofarguments which, beyond being deductions, feature premises which arenecessary and, as Aristotle says, “better known bynature”, or “more intelligible by nature”(gnôrimôteron phusei)(APo. 71b33–72a25;Top. 141b3–14;Phys. 184a16–23). By this he means that they shouldreveal the genuine, mind-independent natures of things.

He further insists that science(epistêmê)—a comparatively broad term inhis usage, since it extends to fields of inquiry like mathematics andmetaphysics no less than the empirical sciences—not only reportsthe facts but also explains them by displaying their priorityrelations (APo. 78a22–28). That is, science explains what isless well known by what is better known and more fundamental, and whatis explanatorily anemic by what is explanatorily fruitful.

We may, for instance, wish to know why trees lose their leaves in theautumn. We may say, rightly, that this is due to the wind blowingthrough them. Still, this is not a deep or general explanation, sincethe wind blows equally at other times of year without the sameresult. A deeper explanation—one unavailable to Aristotle butillustrating his view nicely—is more general, and also morecausal in character: trees shed their leaves because diminishedsunlight in the autumn inhibits the production of chlorophyll, whichis required for photosynthesis, and without photosynthesis trees godormant. Importantly, science should not only record these facts butalso display them in their correct explanatory order. That is,although a deciduous tree which fails to photosynthesize is also atree lacking in chlorophyll production, its failing to producechlorophyll explains its inability to photosynthesize and not theother way around. This sort of asymmetry must be captured inscientific explanation. Aristotle’s method of scientific exposition isdesigned precisely to discharge this requirement.

Science seeks to capture not only the causal priorities in nature,but also its deep, invariant patterns. Consequently, in additionto being explanatorily basic, the first premise in a scientificdeduction will be necessary. So, says Aristotle:

We think we understand a thing without qualification, and not in thesophistic, accidental way, whenever we think we know the cause invirtue of which something is—that it is the cause of that verything—and also know that this cannot be otherwise. Clearly, knowledge (epistêmê) is something of thissort. After all, both those with knowledge and those without itsuppose that this is so—although only those with knowledge areactually in this condition. Hence, whatever is known withoutqualification cannot be otherwise. (APo 71b9–16; cf.APo 71b33–72a5;Top. 141b3–14,Phys.184a10–23;Met. 1029b3–13)

For this reason, science requires more than mere deduction.Altogether, then, the currency of science isdemonstration(apodeixis), where a demonstration is a deduction withpremises revealing the causal structures of the world, set forth so asto capture what is necessary and to reveal what is better known andmore intelligible by nature (APo71b33–72a5,Phys. 184a16–23,EN 1095b2–4).

Aristotle’s approach to the appropriate form of scientific explanationinvites reflection upon a troubling epistemological question: how doesdemonstration begin? If we are to lay out demonstrations such that theless well known is inferred by means of deduction from the betterknown, then unless we reach rock-bottom, we will evidently be forcedeither to continue ever backwards towards the increasingly betterknown, which seems implausibly endless, or lapse into some form ofcircularity, which seems undesirable. The alternative seems to bepermanent ignorance. Aristotle contends:

Some people think that since knowledge obtained via demonstrationrequires the knowledge of primary things, there is no knowledge. Others think that there is knowledge and that all knowledge isdemonstrable. Neither of these views is either true ornecessary. The first group, those supposing that there isno knowledge at all, contend that we are confronted with an infiniteregress. They contend that we cannot know posterior thingsbecause of prior things if none of the prior things is primary. Here what they contend is correct: it is indeed impossible to traversean infinite series. Yet, they maintain, if the regress comes to ahalt, and there are first principles, they will be unknowable, sincesurely there will be no demonstration of first principles—given,as they maintain, that only what is demonstrated can be known. But if it is not possible to know the primary things, then neither canwe know without qualification or in any proper way the things derivedfrom them. Rather, we can know them instead only on the basis ofa hypothesis, to wit,if the primary things obtain, then sotoo do the things derived from them. The other group agrees thatknowledge results only from demonstration, but believes that nothingstands in the way of demonstration, since they admit circular andreciprocal demonstration as possible. (APo. 72b5–21)

Aristotle’s own preferred alternative is clear:

We contend that not all knowledge is demonstrative: knowledge of theimmediate premises is indemonstrable. Indeed, the necessity hereis apparent; for if it is necessary to know the prior things, that is,those things from which the demonstration is derived, and if eventuallythe regress comes to a standstill, it is necessary that these immediatepremises be indemonstrable. (APo. 72b21–23)

In sum, if all knowledge requires demonstration, and alldemonstration proceeds from what is more intelligible by nature to whatis less so, then either the process goes on indefinitely or it comes toa halt in undemonstrated first principles, which are known, and knownsecurely. Aristotle dismisses the only remaining possibility,that demonstration might be circular, rather curtly, with the remarkthat this amounts to ‘simply saying that something is thecase if it is the case,’ by which device ‘it is easy toprove anything’ (APo. 72b32–73a6).

Aristotle’s own preferred alternative, that there are firstprinciples of the sciences graspable by those willing to engage inassiduous study, has caused consternation in many of his readers. InPosterior Analytics ii 19, he describes theprocess by which knowers move from perception to memory, and from memoryto experience (empeiria)—which is a fairly technicalterm in this connection, reflecting the point at which a singleuniversal comes to take root in the mind—and finally fromexperience to a grasp of first principles. This finalintellectual state Aristotle characterizes as a kind of unmediatedintellectual apprehension (nous) of first principles(APo. 100a10–b6).

Scholars have understandably queried what seems a casually assertedpassage from the contingent, given in sense experience, to thenecessary, as required for the first principles of science. Perhaps,however, Aristotle simply envisages a kind ofa posteriorinecessity for the sciences, including the natural sciences. In anyevent, he thinks that we can and do have knowledge, so that somehow webegin in sense perception and build up to an understanding of thenecessary and invariant features of the world. This is the knowledgefeatured in genuine science (epistêmê). Inreflecting on the sort of progression Aristotle envisages, somecommentators have charged him with an epistemological optimismbordering on the naïve; others contend that it is rather thecharge of naïveté which is itself naïve, betraying asit does an unargued and untenable alignment of the necessary andthea priori.^[7]

4.3 Dialectic

Not all rigorous reasoning qualifies as scientific. Indeed,little of Aristotle’s extant writing conforms to the demands forscientific presentation laid down in thePosteriorAnalytics. As he recognizes, we often find ourselvesreasoning from premises which have the status ofendoxa,opinions widely believed or endorsed by the wise, even though they arenot known to be necessary. Still less often do we reason havingfirst secured the first principles of our domain of inquiry. So,we need some ‘method by which we will be able to reasondeductively about any matter proposed to us on the basis ofendoxa, and to give an account of ourselves [when we are underexamination by an interlocutor] without lapsing intocontradiction’ (Top. 100a18–20). This methodhe characterizes asdialectic.

The suggestion that we often use dialectic when engaged inphilosophical exchange reflects Aristotle’s supposition thatthere are two sorts of dialectic: one negative, or destructive, and theother positive, or constructive. In fact, in his work dedicatedto dialectic, theTopics, he identifies three roles fordialectic in intellectual inquiry, the first of which is mainlypreparatory:

Dialectic is useful for three purposes: for training, forconversational exchange, and for sciences of a philosophicalsort. That it is useful for training purposes is directly evidenton the basis of these considerations: once we have a direction for ourinquiry we will more readily be able to engage a subject proposed tous. It is useful for conversational exchange because once we haveenumerated the beliefs of the many, we shall engage them not on thebasis of the convictions of others but on the basis of their own; andwe shall re-orient them whenever they appear to have said somethingincorrect to us. It is useful for philosophical sorts of sciencesbecause when we are able to run through the puzzles on both sides of anissue we more readily perceive what is true and what is false. Further, it is useful for uncovering what is primary among thecommitments of a science. For it is impossible to say anythingregarding the first principles of a science on the basis of the firstprinciples proper to the very science under discussion, since among allthe commitments of a science, the first principles are the primaryones. This comes rather, necessarily, from discussion of thecredible beliefs (endoxa) belonging to the science. Thisis peculiar to dialectic, or is at least most proper to it. Forsince it is what cross-examines, dialectic contains the way to thefirst principles of all inquiries. (Top. 101a26–b4)

The first two of the three forms of dialectic identified by Aristotleare rather limited in scope. By contrast, the third is philosophicallysignificant.

In its third guise, dialectic has a role to play in ‘scienceconducted in a philosophical manner’ (pros tas kataphilosphian epistêmas;Top. 101a27–28, 101a34),where this sort of science includes what we actually find him pursuingin his major philosophical treatises. In these contexts,dialectic helps to sort theendoxa, relegating some to adisputed status while elevating others; it submitsendoxa tocross-examination in order to test their staying power; and, mostnotably, according to Aristotle, dialectic puts us on the road to firstprinciples (Top. 100a18–b4). If that is so, thendialectic plays a significant role in the order of philosophicaldiscovery: we come to establish first principles in part by determiningwhich among our initialendoxa withstand sustainedscrutiny. Here, as elsewhere in his philosophy, Aristotle evincesa noteworthy confidence in the powers of human reason andinvestigation.

5. Essentialism and Homonymy

However we arrive at secure principles in philosophy and science,whether by some process leading to a rational grasping of necessarytruths, or by sustained dialectical investigation operating overjudiciously selectedendoxa, it does turn out, according toAristotle, that we can uncover and come to know genuinely necessaryfeatures of reality. Such features, suggests Aristotle, are thosecaptured in the essence-specifying definitions used in science (againin the broad sense ofepistêmê).

Aristotle’s commitment to essentialism runs deep. Herelies upon a host of loosely related locutions when discussing theessences of things, and these give some clue to his generalorientation. Among the locutions one finds rendered asessence in contemporary translations of Aristotle into Englishare: (i)to ti esti (the what it is); (ii)to einai(being); (iii)ousia (being); (iv)hoper esti (preciselywhat something is) and, most importantly, (v)to ti êneinai (the what it was to be) (APo 83a7;Top.141b35;Phys. 190a17, 201a18–21;Gen. et Corr. 319b4;DA 424a25, 429b10;Met. 1003b24, 1006a32, 1006b13;EN 1102a30, 1130a12–13). Among these, the last locution(v) requires explication both because it is the most peculiar andbecause it is Aristotle’s favored technical term foressence. It is an abbreviated way of saying ‘that which itwas for an instance of kindK to be an instance of kindK,’ for instance ‘that which it was (all along)for a human being to be a human being’. In speaking thisway, Aristotle supposes that if we wish to know what a human being is,we cannot identify transient or non-universal features of that kind;nor indeed can we identify even universal features which do not runexplanatorily deep. Rather, as his preferred locution indicates,he is interested in what makes a human being human—and heassumes, first, that there is some feature F which all and only humanshave in common and, second, that F explains the other features which wefind across the range of humans.

Importantly, this second feature of Aristotelian essentialismdifferentiates his approach from the now more common modal approach,according to which:^[8]

F is an essential property ofx =_df ifx losesF,thenx ceases to exist.

Aristotle rejects this approach for several reasons, including mostnotably that he thinks that certain non-essential features satisfy thedefinition. Thus, beyond the categorical and logical features(everyone is such as to be either identical or not identical with thenumber nine), Aristotle recognizes a category of properties which hecallsidia (Cat. 3a21, 4a10;Top. 102a18–30,134a5–135b6), now usually known by their Medieval Latin renderingpropria. Propria are non-essential properties which flowfrom the essence of a kind, such that they are necessary to that kindeven without being essential. For instance, if we suppose thatbeing rational is essential to human beings, then it willfollow that every human being iscapable of grammar. Being capable of grammar is not the same property as being rational,though it follows from it. Aristotle assumes his readers willappreciate thatbeing rational asymmetrically explainsbeing capable of grammar, even though, necessarily, somethingis rational if and only if it is also capable of grammar. Thus,because it is explanatorily prior,being rational has a betterclaim to being the essence of human beings than doesbeing capableof grammar. Consequently, Aristotle’sessentialism is more fine-grained than mere modal essentialism. Aristotelian essentialism holds:

F is an essential property ofx =_df (i) ifx losesF, thenx ceases to exist; and(ii)F is in an objective sense an explanatorily basicfeature ofx.

In sum, in Aristotle’s approach, what it is to be, forinstance, a human being is just what it always has been and always willbe, namelybeing rational. Accordingly, this isthe feature to be captured in an essence-specifying account of humanbeings (APo 75a42–b2;Met. 103b1–2, 1041a25–32).

Aristotle believes for a broad range of cases that kinds have essencesdiscoverable by diligent research. He in fact does not devotemuch energy to arguing for this contention; still less is he inclinedto expend energy combating anti-realist challenges to essentialism,perhaps in part because he is impressed by the deep regularities hefinds, or thinks he finds, underwriting his results in biological investigation.^[9] Still, he cannot be accused of profligacy regarding the prospectsof essentialism.

On the contrary, he denies essentialism in many cases where othersare prepared to embrace it. One finds this sort of denialprominently, though not exclusively, in his criticism of Plato. Indeed, it becomes a signature criticism of Plato and Platonists forAristotle that many of their preferred examples of sameness andinvariance in the world are actually cases ofmultivocity, orhomonymy in his technical terminology. In the opening of theCategories, Aristotle distinguishes betweensynonymyandhomonymy (later calledunivocity andmultivocity). His preferred phrase for multivocity,which is extremely common in his writings, is ‘being spokenof in many ways’, or, more simply, ‘multiply meant’(pollachôs legomenon). All these locutions have aquasi-technical status for him. The least complex isunivocity:

a andb are univocallyF iff (i)a isF, (ii)b isF, and (iii) theaccounts ofF-ness in ‘a isF’ and‘b isF’ are the same.

Thus, for instance, since the accounts of ‘human’ in‘Socrates is human’ and ‘Plato is human’ willbe the same, ‘human’ is univocal or synonymous in theseapplications. (Note that Aristotle’s notion of the word ‘synonymy’ isnot the same as the contemporary English usage where it applies todifferent words with the same meaning.) In cases ofunivocity, we expect single, non-disjunctive definitions which captureand state the essence of the kinds in question. Let us allow oncemore for purposes of illustration that the essence-specifyingdefinition ofhuman isrational animal. Then,sincehuman meansrational animal across the range ofits applications, there is some single essence to all members of thekind.

By contrast, when synonymy fails we have homonymy. According toAristotle:

a andb are homonymouslyF iff (i)a isF, (ii)b isF, (iii) theaccounts ofF-ness in ‘a isF’and ‘b isF’ do not completelyoverlap.

To take an easy example without philosophical significance,bank is homonymous in ‘Socrates and Alcibiades had apicnic on the bank’ and ‘Socrates and Alcibiades opened ajoint account at the bank.’ This case is illustrative, ifuninteresting, because the accounts ofbank in theseoccurrences have nothing whatsoever in common. Part of the philosophical interest in Aristotle’s account of homonymy resides in itsallowing partial overlap. Matters become more interesting if weexamine whether—to use an illustration well suited toAristotle’s purposes but left largely unexplored byhim—conscious is synonymous across ‘Charlene wasconscious of some awkwardness created by her remarks’ and‘Higher vertebrates, unlike mollusks, are conscious.’ In these instances, the situation with respect to synonymy or homonymyis perhaps not immediately clear, and so requires reflection andphilosophical investigation.

Very regularly, according to Aristotle, this sort of reflection leadsto an interesting discovery, namely that we have been presuming aunivocal account where in fact none is forthcoming. This,according to Aristotle, is where the Platonists go wrong: they presumeunivocity where the world delivers homonymy or multivocity. (Fora vivid illustration of Plato’s univocity assumption at work, seeMeno 71e1–72a5, where Socrates insists that there is but onekind ofexcellence (aretê) common to all kindsof excellent people, not a separate sort for men, women, slaves,children, and so on.) In one especially important example,Aristotle parts company with Plato over the univocity of goodness:

We had perhaps better consider the universal good and run throughthe puzzles concerning what is meant by it—even though this sortof investigation is unwelcome to us, because those who introduced theForms are friends of ours. Yet presumably it would be the bettercourse to destroy even what is close to us, as something necessary forpreserving the truth—and all the more so, given that we arephilosophers. For though we love them both, piety bids us tohonour the truth before our friends. (EN1096a11–16)

Aristotle counters that Plato is wrong to assume that goodness is‘something universal, common to all good things, andsingle’ (EN 1096a28). Rather, goodness is different indifferent cases. If he is right about this, far-reaching consequencesregarding ethical theory and practice follow.

To establish non-univocity, Aristotle’s appeals to a variety oftests in hisTopics where, again, his idiom is linguistic buthis quarry is metaphysical. Consider the following sentences:

• Socrates is good.
• Communism is good.
• After a light meal, crème brûlée is good.
• Redoubling one’s effort after failure is always good.
• Maria’s singing is good, but Renata’s is sublime.

Among the tests for non-univocity recommended in theTopicsis a simple paraphrase test: if paraphrases yield distinct,non-interchangeable accounts, then the predicate ismultivocal. So, for example, suitable paraphrases mightbe:

• Socrates isa virtuousperson.
• Communism is ajust socialsystem.
• After a light meal,crème brûlée istasty and satisfying.
• Trying harder after one hasfailed is alwaysedifying.
• Maria’s singingreaches a high artistic standard, but Renata’ssurpasses that standard by any measure.

Since we cannot interchange these paraphrases—we cannot say,for instance, that crème brûlée is a just socialsystem—good must be non-univocal across this range ofapplications. If that is correct, then Platonists are wrong toassume univocity in this case, since goodness exhibits complexityignored by their assumption.

So far, then, Aristotle’s appeals to homonymy or multivocity areprimarily destructive, in the sense that they attempt to undermine aPlatonic presumption regarded by Aristotle as unsustainable. Importantly, just as Aristotle sees a positive as well as a negativerole for dialectic in philosophy, so he envisages in addition to itsdestructive applications a philosophically constructive role forhomonymy. To appreciate his basic idea, it serves to reflect upon acontinuum of positions in philosophical analysis ranging from purePlatonic univocity to disaggregated Wittgensteinean familyresemblance. One might in the face of a successful challenge toPlatonic univocity assume that, for instance, the various cases ofgoodness have nothing in common across all cases, so that good thingsform at best a motley kind, of the sort championed by Wittgensteineansenamored of the metaphor of family resemblances: all good things belongto a kind only in the limited sense that they manifest a tapestry ofpartially overlapping properties, as every member of a single family isunmistakably a member of that family even though there is no onephysical attribute shared by all of those family members.

Aristotle insists that there is atertium quid between familyresemblance and pure univocity: he identifies, and trumpets, a kind ofcore-dependent homonymy (also referred to in the literature,with varying degrees of accuracy, asfocal meaning andfocal connexion).^[10] Core-dependent homonyms exhibit a kindof order in multiplicity: although shy of univocity, becausehomonymous, such concepts do not devolve into patchwork familyresemblances either. To rely upon one of Aristotle’s ownfavorite illustrations, consider:

• Socrates is healthy.
• Socrates’ exercise regimen is healthy.
• Socrates’ complexion is healthy.

Aristotle assumes that his readers will immediately appreciate twofeatures of these three predications ofhealthy. First,they are non-univocal, since the second is paraphraseable roughly aspromotes health and the third asis indicative ofhealth, whereas the first means, rather, something morefundamental, likeis sound of body oris functioningwell. Hence,healthy is non-univocal. Second,even so, the last two predications rely upon the first for theirelucidations: each appeals to health in its core sense in anasymmetrical way. That is, any account of each of the latter twopredicationsmust allude to the first, whereas an account ofthe first makes no reference to the second or third in itsaccount. So, suggests Aristotle,health is not only ahomonym, but acore-dependent homonym: while not univocalneither is it a case of rank multivocity.

Aristotle’s illustration does succeed in showing that there isconceptual space between mere family resemblance and pureunivocity. So, he is right that these are not exhaustiveoptions. The interest in this sort of result resides in itsexportability to richer, if more abstract philosophical concepts. Aristotle appeals to homonymy frequently, across a full range ofphilosophical concepts includingjustice,causation,love,life,sameness,goodness, andbody. His most celebrated appeal to core-dependent homonymycomes in the case of a concept so highly abstract that it is difficultto gauge his success without extended metaphysical reflection. This ishis appeal to the core-dependent homonymy ofbeing, which hasinspired both philosophical and scholarlycontroversy.^[11]Aristotle denies that there could be a science of being, on thegrounds that there is no single genusbeing under which alland only beings fall (SE 11172a13–15–15;APr. 92b14;Met. B 3,998b22;EE i 8, 1217b33–35). One motivation for hisreasoning this way may be that he regards the notion of a genus as ineliminably taxonomical and contrastive,^[12] so that it makes ready sense to speak ofa genus of being only if one can equally well speak of a genus ofnon-being—just as among living beings one can speak of theanimals and the non-animals, viz. the plant kingdom. Since there areno non-beings, there accordingly can be no genus of non-being, and so,ultimately, no genus of being either. Consequently, since eachscience studies one essential kind arrayed under a single genus, therecan be no science of being either.

Subsequently, without expressly reversing his judgment about theexistence of a science of being, Aristotle announces that there isnonetheless a science of beingqua being (Met. iv 4),first philosophy, which takes as its subject matter beings insofar asthey are beings and thus considers all and only those featurespertaining to beings as such—to beings, that is, not insofar asthey are mathematical or physical or human beings, but insofar as theyare beings, full stop. Although the matter is disputed, hisrecognition of this science evidently turns crucially on his commitmentto the core-dependent homonymy of being itself.^[13] Although the case is notas clear and uncontroversial as Aristotle’s relatively easyappeal tohealth (which is why, after all, he selected it asan illustration), we are supposed to be able upon reflection to detectan analogous core-dependence in the following instances ofexists:

• Socrates exists.
• Socrates’ location exists.
• Socrates’ weighing 73 kilos exists.
• Socrates’ being morose today exists.

Of course, the last three items on this list are rather awkwardlocutions, but this is because they strive to make explicit that we canspeak of dependent beings as existing if we wish to do so—butonly because of their dependence upon the core instance of being,namely substance. (Here it is noteworthy that ‘primarysubstance’ is the conventional and not very happy rendering ofAristotle’sprotêousia in Greek, whichmeans, more literally, ‘primary being’).^[14] According to thisapproach, we would not have Socrates’ weighing anything at all orfeeling any way today were it not for the prior fact of hisexistence. So,exists in the first instance serves asthe core instance of being, in terms of which the others are to beexplicated. If this is correct, then, implies Aristotle,being is a core-dependent homonym; further, a science ofbeing—or, rather, a science of beingquabeing—becomes possible, even though there is no genus of being,since it is finally possible to study all beings insofar as they arerelated to the core instance of being, and then also to study thatcore instance, namely substance, insofar as it serves as the primeoccasion of being.

6. Category Theory

In speaking of beings which depend upon substance for their existence,Aristotle implicitly appeals to a foundational philosophical commitmentwhich appears early in his thought and remains stable throughout hisentire philosophical career: his theory of categories. In what isusually regarded as an early work,The Categories, Aristotlerather abruptly announces:

Of things said without combination, each signifies either: (i) asubstance (ousia); (ii) a quantity; (iii) a quality; (iv) arelative; (v) where; (vi) when; (vii) being in a position; (viii)having; (ix) acting upon; or (x) a being affected. (Cat.1b25–27)

Aristotle does little to frame his theory of categories, offering noexplicit derivation of it, nor even specifying overtly what his theoryof categories categorizes. If librarians categorize books andbotanists categorize plants, then what does the philosophical categorytheorist categorize?

Aristotle does not say explicitly, but his examples make reasonablyclear that he means to categorize the basic kinds of beings there maybe. If we again take some clues from linguistic data, withoutinferring that the ultimate objects of categorization are themselveslinguistic, we can contrast things said “withcombination”:

• Man runs.

with things said ‘without combination’:

• Man
• Runs

‘Man runs’ is truth-evaluable, whereas neither ‘man’ nor ‘runs’ is. Aristotle says thatthings of this sortsignify entities, evidentlyextra-linguistic entities, which are thus, correlatively, in the firstcase sufficiently complex to be what makes the sentence ‘Manruns’ true, that is aman running, and in the second,items below the level of truth-making, so, e.g., an entitya man,taken by itself, and an actionrunning, taken by itself. If that is correct, the entities categorized by the categories are thesorts of basic beings that fall below the level of truth-makers, orfacts. Such beings evidently contribute, so to speak, to thefacticity of facts, just as, in their linguistic analogues, nouns andverbs, things said ‘without combination’, contribute to thetruth-evaluability of simple assertions. The constituents offacts contribute to facts as the semantically relevant parts of aproposition contribute to its having the truth conditions it has. Thus, the items categorized in Aristotle’s categories are theconstituents of facts. If it is a factthat Socrates ispale, then the basic beings in view areSocrates andbeing pale. In Aristotle’s terms, the firstis asubstance and the second is aquality.

Importantly, these beings may bebasic without beingabsolutelysimple. After all, Socrates is made up of allmanner of parts—arms and legs, organs and bones, molecules andatoms, and so on down. As a useful linguistic analogue, we mayconsiderphonemes, which are basic, relative to the morphemesof a linguistic theory, and yet also complex, since they are made up ofsimpler sound components, which are irrelevant from thelinguist’s point of view because of their lying beneath the levelof semantic relevance.

The theory of categories in total recognizes ten sorts ofextra-linguistic basic beings:

Although he does not say so overtly in theCategories,Aristotle evidently presumes that these ten categories of being areboth exhaustive and irreducible, so that while there are no otherbasic beings, it is not possible to eliminate any one of thesecategories in favor of another.

Both claims have come in for criticism, and each surely requires defense.^[15]Aristotle offers neither conviction a defense in hisCategories. Nor, indeed, does he offer any principledgrounding for just these categories of being, a circumstance which hasleft him open to further criticism from later philosophers, includingfamously Kant who, after lauding Aristotle for coming up with the ideaof category theory, proceeds to excoriate him for selecting hisparticular categories on no principled basis whatsoever. Kantalleges that Aristotle picked his categories of being just as hehappened to stumble upon them in his reveries (Critique of PureReason, A81/B107). According to Kant, then,Aristotle’s categories areungrounded. Philosophers and scholars both before and after Kant have sought toprovide the needed grounding, whereas Aristotle himself mainly tends tojustify the theory of categories by putting it to work in his variousphilosophical investigations.

We have already implicitly encountered in passing two ofAristotle’s appeals to category theory: (i) in his approach totime, which he comes to treat as a non-substantial being; and (ii) in hiscommitment to the core-dependent homonymy of being, which introducessome rather more contentious considerations. These may berevisited briefly to illustrate how Aristotle thinks that his doctrineof categories provides philosophical guidance where it is mostneeded.

Thinking first of time and its various puzzles, oraporiai,we saw that Aristotle poses a simple question: does time exist? He answers this question in the affirmative, but only because in theend he treats it as a categorically circumscribed question. He claims that ‘time is the measure of motion with respect to thebefore and after’ (Phys. 219b1–2). Byoffering this definition, Aristotle is able to advance the judgmentthat time does exist, because it is an entity in the category ofquantity: time is to motion or change as length is to a line. Time thus exists, but like all items in any non-substance category, itexists in a dependent sort of way. Just as if there were no linesthere would be no length, so if there were no change there would be notime. Now, this feature of Aristotle’s theory of time hasoccasioned both critical and favorable reactions.^[16] In the present context,however, it is important only that it serves to demonstrate howAristotle handles questions of existence: they are, at root, questionsabout category membership. A question as to whether, e.g.,universals or places or relations exist, is ultimately, for Aristotle,also a question concerning their category of being, if any.

As time is a dependent entity in Aristotle’s theory, so too areall entities in categories outside of substance. This helpsexplain why Aristotle thinks it appropriate to deploy his apparatus ofcore-dependent homonymy in the case ofbeing. If we askwhether qualities or quantities exist, Aristotle will answer in theaffirmative, but then point out also that as dependent entities they donot exist in the independent manner of substances. Thus, even inthe relatively rarified case ofbeing, the theory ofcategories provides a reason for uncovering core-dependenthomonymy. Since all other categories of being depend uponsubstance, it should be the case that an analysis of any one of themwill ultimately make asymmetrical reference to substance. Aristotlecontends in hisCategories, relying on a distinction thattracks essential (said-of) and accidental (in)predication, that:

All other things are eithersaid-of primarysubstances, which are their subjects, or arein them assubjects. Hence, if there were no primary substances, it would beimpossible for anything else to exist. (Cat. 2b5–6)

If this is so, then, Aristotle infers, all the non-substancecategories rely upon substance as the core of their being. So, heconcludes, being qualifies as a case of core-dependent homonymy.

Now, one may challenge Aristotle’s contentions here, first byquerying whether he has established the non-univocity ofbeingbefore proceeding to argue for its core-dependence. Be that as itmay, if we allow its non-univocity, then, according to Aristotle, theapparatus of the categories provides ample reason to conclude thatbeing qualifies as a philosophically significant instance ofcore-dependent homonymy.

In this way, Aristotle’s philosophy of being and substance, likemuch else in his philosophy, relies upon an antecedent commitment tohis theory of categories. Indeed, the theory of categoriesspans his entire career and serves as a kind of scaffolding for much ofhis philosophical theorizing, ranging from metaphysics and philosophyof nature to psychology and value theory.

For this reason, questions regarding the ultimate tenability ofAristotle’s doctrine of categories take on a special urgency forevaluating much of his philosophy.

For more detail on the theory of categories and its grounding, see the entry onAristotle’s Categories.

7. The Four Causal Account of Explanatory Adequacy

Equally central to Aristotle’s thought is hisfour-causalexplanatory scheme. Judged in terms of its influence, thisdoctrine is surely one of his most significant philosophicalcontributions. Like other philosophers, Aristotle expects theexplanations he seeks in philosophy and science to meet certaincriteria of adequacy. Unlike some other philosophers, however, hetakes care to state his criteria for adequacy explicitly; then, havingdone so, he finds frequent fault with his predecessors for failing tomeet its terms. He states his scheme in a methodological passagein the second book of hisPhysics:

One way in which cause is spoken of is that out of which a thingcomes to be and which persists, e.g. the bronze of the statue, thesilver of the bowl, and the genera of which the bronze and the silverare species.

In another way cause is spoken of as the form or the pattern, i.e.what is mentioned in the account (logos) belonging to theessence and its genera, e.g. the cause of an octave is a ratio of 2:1,or number more generally, as well as the parts mentioned in the account(logos).

Further, the primary source of the change and rest is spoken of as acause, e.g. the man who deliberated is a cause, the father is the causeof the child, and generally the maker is the cause of what is made andwhat brings about change is a cause of what is changed.

Further, the end (telos) is spoken of as a cause. This is that for the sake of which (houheneka) athing is done, e.g. health is the cause of walking about. ‘Why is he walking about?’ We say: ‘To behealthy’—and, having said that, we think we have indicatedthe cause.

(Phys. 194b23–35)

Although some of Aristotle’s illustrations are not immediatelypellucid, his approach to explanation is reasonablystraightforward.

Aristotle’s attitude towards explanation is best understoodfirst by considering a simple example he proposes inPhysicsii 3. A bronze statue admits of various different dimensions ofexplanation. If we were to confront a statue without firstrecognizing what it was, we would, thinks Aristotle, spontaneously aska series of questions about it. We would wish to knowwhat itis, what it is made of,what brought it about,andwhat it is for. In Aristotle’s terms, inasking these questions we are seeking knowledge of the statue’sfourcauses (aitia): the formal, material, efficient,and final. According to Aristotle, when we haveidentified these four causes, we have satisfied a reasonable demand forexplanatory adequacy.

More fully, the four-causal account of explanatory adequacy requiresan investigator to cite these four causes:

InPhysics ii 3, Aristotle makes twin claims about thisfour-causal schema: (i) that citing all four causes isnecessary for adequacy in explanation; and (ii) that thesefour causes aresufficient for adequacy in explanation. Each of these claims requires some elaboration and also somequalification.

As for the necessity claim, Aristotle does not suppose that allphenomena admit of all four causes. Thus, for example,coincidences lack final causes, since they do not occur for the sake ofanything; that is, after all, what makes them coincidences. If a debtor is on his way to the market to buy milk and she runs intoher creditor, who is on his way to the same market to buy bread, thenshe may agree to pay the money owed immediately. Althoughresulting in a wanted outcome, their meeting was not for the sake ofsettling the debt; nor indeed was it for the sake of anything atall. It was a simple co-incidence. Hence, it lacks a finalcause. Similarly, if we think that there are mathematical orgeometrical abstractions, for instance a triangle existing as an objectof thought independent of any material realization, then the trianglewill trivially lack a material cause.^[17] Still, these significant exceptionsaside, Aristotle expects the vast majority of explanations to conformto his four-causal schema. In non-exceptional cases, a failure tospecify all four of causes, is, he maintains, a failure in explanatoryadequacy.

The sufficiency claim is exceptionless, though it may yet be misleadingif one pertinent issue is left unremarked. In providing hisillustration of the material cause Aristotle first cites the bronze ofa statue and the silver of a bowl, and then mentions also ‘thegenera of which the bronze and the silver are species’(Phys. 194b25–27). By this he means the types of metalto which silver and bronze belong, or more generally still, simplymetal. That is, one might specify the material cause ofa statue more or less proximately, by specifying the character of thematter more or less precisely. Hence, when he implies that citingall four causes is sufficient for explanation, Aristotle does notintend to suggest that a citation at any level of generalitysuffices. He means to insist rather that there is no fifth kindof cause, that his preferred four cases subsume all kinds ofcause. He does not argue for this conclusion fully, though hedoes challenge his readers to identify a kind of cause which qualifiesas a sort distinct from the four mentioned (Phys.195a4–5).

So far, then, Aristotle’s four causal schema has whateverintuitive plausibility his illustrations may afford it. He doesnot rest content there, however. Instead, he thinks he can argueforcefully for the four causes as real explanatory factors, that is, asfeatures which must be cited not merely because they make forsatisfying explanations, but because they are genuinely operativecausal factors, the omission of which renders any putative explanationobjectively incomplete and so inadequate.

It should be noted that Aristotle’s arguments for the four causestaken individually all proceed against the backdrop of the generalconnection he forges between causal explanation and knowledge. Becausehe thinks that the fouraitia feature in answers toknowledge-seeking questions (Phys. 194b18;A Po. 71 b9–11, 94 a 20), some scholars have come to understand them more asbecauses than ascauses—that is, asexplanations rather than as causes narrowly construed.^[18] Most such judgmentsreflect an antecedent commitment to one or another view of causationand explanation—that causation relates events rather thanpropositions; that explanations are inquiry-relative; that causation isextensional and explanation intensional; that explanations must adhereto some manner of nomic-deductive model, whereas causes need not; orthat causes must be prior in time to their effects, while explanations,especially intentional explanations, may appeal to states of affairsposterior in time to the actions they explain.

Generally, Aristotle does not respect these sorts ofcommitments. Thus, to the extent that they are defensible, hisapproach toaitia may be regarded as blurring the canons ofcausation and explanation. It should certainly not, however, beceded up front that Aristotle is guilty of any such conflation, or eventhat scholars who render his account of the fouraitia incausal terms have failed to come to grips with developments in causaltheory in the wake of Hume. Rather, because of the lack ofuniformity in contemporary accounts of causation and explanation, and apersistent and justifiable tendency to regard causal explanations asfoundational relative to other sorts of explanations, we maylegitimately wonder whether Aristotle’s conception of the fouraitia is in any significant way discontinuous with later,Humean-inspired approaches, and then again, to the degree that it is,whether Aristotle’s approach suffers for the comparison. Be thatas it may, we will do well when considering Aristotle’s defenseof his fouraitia to bear in mind that controversy surroundshow best to construe his knowledge-driven approach to causation andexplanation relative to some later approaches.

For more on the four causes in general, see the entry onAristotle on Causality.

8. Hylomorphism

Central to Aristotle’s four-causal account of explanatoryadequacy are the notions ofmatter (hulê) andform (eidos ormorphê). Together, theyconstitute one of his most fundamental philosophical commitments, tohylomorphism:

• Hylomorphism =_dfordinary objects are composites of matter and form.

The appeal in this definition to ‘ordinary objects’requires reflection, but as a first approximation, it serves to rely onthe sorts of examples Aristotle himself employs when motivatinghylomorphism: statues and houses, horses and humans. In general,we may focus on artefacts and familiar living beings. Hylomorphism holds that no such object is metaphysically simple, butrather comprises two distinct metaphysical elements, one formal and onematerial.

Aristotle’s hylomorphism was formulated originally to handlevarious puzzles about change. Among theendoxaconfronting Aristotle in hisPhysics are some strikingchallenges to the coherence of the very notion of change, owing toParmenides andZeno. Aristotle’s initial impulse in the face of such challenges, as wehave seen, is to preserve the appearances (phainomena), toexplain how change is possible. Key to Aristotle’s responseto the challenges bequeathed him is his insistence that all changeinvolves at least two factors: something persisting and somethinggained or lost. Thus, when Socrates goes to the beach and comesaway sun-tanned, something continues to exist, namely Socrates, evenwhile something is lost, his pallor, and something else gained, histan. This is a change in the category of quality, whence thecommon locution ‘qualitative change’. If he gainsweight, then again something remains, Socrates, and something is gained,in this case a quantity of matter. Accordingly, in this instance wehave not a qualitative but a quantitative change.

In general, argues Aristotle, in whatever category a change occurs,something is lost and something gainedwithin that category,even while something else, a substance, remains in existence, as thesubject of that change. Of course, substances can come into or go out ofexistence, in cases ofgeneration or destruction; and these are changes in the category ofsubstance. Evidently even in cases of change in this category, however,something persists. To take an example favourable to Aristotle,in the case of the generation of a statue, the bronze persists, but itcomes to acquire a new form, a substantial rather than accidentalform. In all cases, whether substantial or accidental, thetwo-factor analysis obtains: something remains the same and somethingis gained or lost.

In its most rudimentary formulation, hylomorphism simply labels each ofthe two factors: what persists ismatter and what is gained isform. Aristotle’s hylomorphism quickly becomesmuch more complex, however, as the notions of matter and form arepressed into philosophical service. Importantly, matter and formcome to be paired with another fundamental distinction, that betweenpotentiality andactuality. Again in the caseof the generation of a statue, we may say that the bronze ispotentially a statue, but that it is anactual statuewhen and only when it is informed with the form of astatue. Of course, before being made into a statue, thebronze was also in potentiality a fair number of otherartefacts—a cannon, a steam-engine, or a goal on a footballpitch. Still, it was not in potentiality butter or a beachball. This shows that potentiality is not the same aspossibility: to say thatx is potentially F is to say thatx already has actual features in virtue of which it might bemade to be F by the imposition of a F form upon it. So, giventhese various connections, it becomes possible to define form andmatter generically as

• form =_df that which makes some matter which ispotentiallyF actuallyF
• matter =_df that which persists and which is, for somerange ofFs, potentiallyF

Of course, these definitions are circular, but that is not in itselfa problem: actuality and potentiality are, for Aristotle, fundamentalconcepts which admit of explication and description but do not admit ofreductive analyses.

Encapsulating Aristotle’s discussions of change inPhysics i 7 and 8, and putting the matter more crisply than hehimself does, we have the following simple argument for matter andform: (1) a necessary condition of there being change is the existenceof matter and form; (2) there is change; hence (3) there are matter andform. The second premise is aphainomenon; so, if thatis accepted without further defense, only the first requiresjustification. The first premise is justified by the thought that sincethere is no generationex nihilo, in every instance of changesomething persists while something else is gained or lost. Insubstantial generation or destruction, a substantial form is gained orlost; in mere accidental change, the form gained or lost is itselfaccidental. Since these two ways of changing exhaust the kinds ofchange there are, inevery instance of change there are twofactors present. These are matter and form.

For these reasons, Aristotle intends his hylomorphism to be much morethan a simple explanatory heuristic. On the contrary, he maintains,matter and form are mind-independent features of the world and must,therefore, be mentioned in any full explanation of its workings.

9. Aristotelian Teleology

We may mainly pass over as uncontroversial the suggestion that thereare efficient causes in favor of the most controversial and difficultof Aristotle four causes, the final cause.^[19] We should note before doing so, however, that Aristotle’s commitmentto efficient causation does receive a defense in Aristotle’s preferredterminology; he thus does more than many other philosophers who takeit as given that causes of an efficient sort are operative. Partly byway of criticizing Plato’s theory of Forms, which he regards asinadequate because of its inability to account for change andgeneration, Aristotle observes that nothing potential can bring itselfinto actuality without the agency of an actually operative efficientcause. Since what is potential is always in potentiality relative tosome range of actualities, and nothing becomes actual of its ownaccord—no pile of bricks, for instance, spontaneously organizesitself into a house or a wall—an actually operative agent isrequired for every instance of change. This is the efficientcause. These sorts of considerations also incline Aristotle to speakof the priority of actuality over potentiality: potentialities aremade actual by actualities, and indeed are always potentialities forsome actuality or other. The operation of some actuality upon somepotentiality is an instance of efficient causation.

That said, most of Aristotle’s readers do not find themselves in needof a defense of the existence of efficient causation. By contrast,most think that Aristotle does need to provide a defense of finalcausation. It is natural and easy for us to recognize final causalactivity in the products of human craft: computers and can-openers aredevices dedicated to the execution of certain tasks, and both theirformal and material features will be explained by appeal to theirfunctions. Nor is it a mystery where artefacts obtain their functions:we give artefacts their functions. The ends of artefacts are the results ofthe designing activities of intentional agents. Aristotle recognizesthese kinds of final causation, but also, and more problematically,envisages a much greater role for teleology in natural explanation:nature exhibits teleology without design. He thinks, for instance,that living organisms not only have parts which require teleologicalexplanation—that, for instance, kidneys areforpurifying the blood and teeth arefor tearing and chewingfood—but that whole organisms, human beings and other animals,also have final causes.

Crucially, Aristotle denies overtly that the causes operative innature are intention-dependent. He thinks, that is, thatorganisms have final causes, but that they did not come to have them bydint of the designing activities of some intentional agent orother. He thus denies that a necessary condition ofx’s having a final cause isx’s beingdesigned.

Although he has been persistently criticized for his commitment tosuch natural ends, Aristotle is not susceptible to a fair number ofthe objections standardly made to his view. Indeed, it is evidentthat whatever the merits of the most penetrating of such criticisms,much of the contumely directed at Aristotle is stunningly illiterate.^[20] To take but one of any number of mind-numbing examples, the famousAmerican psychologist B. F. Skinner reveals that ‘Aristotleargued that a falling body accelerated because it grew more jubilantas it found itself nearer its home’ (1971, 6). To anyone who hasactually read Aristotle, it is unsurprising that this ascription comeswithout an accompanying textual citation. For Aristotle, as Skinnerwould portray him, rocks are conscious beings having end states whichthey so delight in procuring that they accelerate themselves inexaltation as they grow ever closer to attaining them. There is noexcuse for this sort of intellectual slovenliness, when already by thelate-nineteenth century, the German scholar Zeller was able to saywith perfect accuracy that ‘The most important feature of theAristotelian teleology is the fact that it is neither anthropocentricnor is it due to the actions of a creator existing outside the worldor even of a mere arranger of the world, but is always thought of asimmanent in nature’ (1883, §48).

Indeed, it is hardly necessary to caricature Aristotle’steleological commitments in order to bring them into criticalfocus. In fact, Aristotle offers two sorts of defenses ofnon-intentional teleology in nature, the first of which is replete withdifficulty. He claims inPhysics ii 8:

For these [viz. teeth and all other parts of naturalbeings] and all other natural things come about as they do eitheralways or for the most part, whereas nothing which comes about due tochance or spontaneity comes about always or for the most part. … If, then, these are either the result of coincidence or for thesake of something, and they cannot be the result of coincidence orspontaneity, it follows that they must be for the sake ofsomething. Moreover, even those making these sorts of claims[viz. that everything comes to be by necessity] will agree that suchthings are natural. Therefore, that for the sake of which ispresent among things which come to be and exist by nature.(Phys. 198b32–199a8)

The argument here, which has been variously formulated by scholars,^[21]seems doubly problematic.

In this argument Aristotle seems to introduce as aphainomenonthat nature exhibits regularity, so that the parts of nature come aboutin patterned and regular ways. Thus, for instance, humanstend to have teeth arranged in a predictable sort of way, with incisorsin the front and molars in the back. He then seems to contend, asan exhaustive and exclusive disjunction, that things happen either bychance or for the sake of something, only to suggest, finally, thatwhat is ‘always or for the most part’—what happens ina patterned and predictable way—is not plausibly thought to bedue to chance. Hence, he concludes, whatever happens always orfor the most part must happen for the sake of something, and so mustadmit of a teleological cause. Thus, teeth show up always or forthe most part with incisors in the front and molars in the back; sincethis is a regular and predictable occurrence, it cannot be due tochance. Given that whatever is not due to chance has a finalcause, teeth have a final cause.

If so much captures Aristotle’s dominant argument for teleology, thenhis view is unmotivated. The argument is problematic in the firstinstance because it assumes an exhaustive and exclusive disjunctionbetween what is by chance and what is for the sake of something. Butthere are obviously other possibilities. Hearts beat not in order tomake noise, but they do so always and not by chance. Second, and thisis perplexing if we have represented him correctly, Aristotle ishimself aware of one sort of counterexample to this view and is indeedkeen to point it out himself: although, he insists, bile is regularlyand predictably yellow, its being yellow is neither due simply tochance nor for the sake of anything. Aristotle in fact mentions manysuch counterexamples (Part. An. 676b16–677b10,Gen. An. 778a29–b6). It seems to follow, then, short ofascribing a straight contradiction to him, either that he is notcorrectly represented as we have interpreted this argument or that hesimply changed his mind about the grounds of teleology. Taking upthe first alternative, one possibility is that Aristotle is not reallytrying toargue for teleology from the ground up inPhysics ii 8, but is taking it as already established thatthere are teleological causes, and restricting himself to observingthat many natural phenomena, namely those which occur always or for themost part, are good candidates for admitting of teleologicalexplanation.

That would leave open the possibility of a broader sort of motivationfor teleology, perhaps of the sort Aristotle offers elsewhere in thePhysics, when speaking about the impulse to findnon-intention-dependent teleological causes at work in nature:

This is most obvious in the case of animals other than man:they make things using neither craft nor on the basis of inquiry nor bydeliberation. This is in fact a source of puzzlement for thosewho wonder whether it is by reason or by some other faculty that thesecreatures work—spiders, ants and the like. Advancing bit bybit in this same direction it becomes apparent that even in plantsfeatures conducive to an end occur—leaves, for example, grow inorder to provide shade for the fruit. If then it is both bynature and for an end that the swallow makes its nest and the spiderits web, and plants grow leaves for the sake of the fruit and sendtheir roots down rather than up for the sake of nourishment, it isplain that this kind of cause is operative in things which come to beand are by nature. And since nature is twofold, as matter and asform, the form is the end, and since all other things are for sake ofthe end, the form must be the cause in the sense of that for the sakeof which. (Phys. 199a20–32)

As Aristotle quite rightly observes in this passage, we findourselves regularly and easily speaking in teleological terms whencharacterizing non-human animals and plants. It is consistentwith our so speaking, of course, that all of our easy language in thesecontexts is rather too easy: it is in fact lax and careless, because unwarrantedlyanthropocentric. We might yet demand that all such language beassiduously reduced to some non-teleological idiom when we are beingscientifically strict and empirically serious, though we would firstneed to survey the explanatory costs and benefits of our attempting todo so. Aristotle considers and rejects some views hostile toteleology inPhysics ii 8 andGeneration andCorruption i.^[22]

10. Substance

Once Aristotle has his four-causal explanatory schema fully on thescene, he relies upon it in virtually all of his most advancedphilosophical investigation. As he deploys it in variousframeworks, we find him augmenting and refining the schema even as heapplies it, sometimes with surprising results. One importantquestion concerns how his hylomorphism intersects with the theory ofsubstance advanced in the context of his theory of categories.

As we have seen, Aristotle insists upon the primacy of primarysubstance in hisCategories. According to that work, however,star instances of primary substance are familiar living beings likeSocrates or an individual horse (Cat. 2a11014). Yet with theadvent of hylomorphism, these primary substances are revealed to bemetaphysical complexes: Socrates is a compound of matter and form. So,now we have not one but three potential candidates for primarysubstance: form, matter, and the compound of matter and form. Thequestion thus arises: which among them is the primary substance? Isit the matter, the form, or the compound? The compound corresponds toa basic object of experience and seems to be a basic subject ofpredication: we say that Socrates lives in Athens, not that his matterlives in Athens. Still, matter underlies the compound and in this wayseems a more basic subject than the compound, at least in the sensethat it can exist before and after it does. On the other hand, thematter is nothing definite at all until enformed; so, perhaps form, asdetermining what the compound is, has the best claim onsubstantiality.

In the middle books of hisMetaphysics, which contain some ofhis most complex and engaging investigations into basic being,Aristotle settles onform (Met. vii 17). Aquestion thus arises as to how form satisfies Aristotle’s finalcriteria for substantiality. He expects a substance to be, as he says,some particular thing (tode ti), but also to be somethingknowable, some essence or other. These criteria seem to pull indifferent directions, the first in favor of particular substances, asthe primary substances of theCategories had been particulars,and the second in favor of universals as substances, because they aloneare knowable. In the lively controversy surrounding thesematters, many scholars have concluded that Aristotle adopts a third wayforward: form is both knowableand particular. This matter,however, remains very acutely disputed.^[23]

Very briefly, and not engaging these controversies, it becomes clearthat Aristotle prefers form in virtue of its role in generation anddiachronic persistence. When a statue is generated, or when a newanimal comes into being, something persists, namely the matter, whichcomes to realize the substantial form in question. Even so,insists Aristotle, the matter does not by itself provide the identityconditions for the new substance. First, as we have seen, thematter is merely potentially someF until such time as it is madeactuallyF by the presence of anF form. Further, the matter canbe replenished, andis replenished in the case of allorganisms, and so seems to be form-dependent for its own diachronicidentity conditions. For these reasons, Aristotle thinks of theform as prior to the matter, and thus more fundamental than thematter. This sort of matter, the form-dependent matter, Aristotleregards asproximate matter (Met. 1038b6, 1042b10),thus extending the notion of matter beyond its original role asmetaphysical substrate.

Further, inMetaphysics vii 17 Aristotle offers a suggestiveargument to the effect that matter alone cannot be substance. Let thevarious bits of matter belonging to Socrates be labeled asa,b,c, …,n. Consistent with thenon-existence of Socrates is the existenceofa,b,c, …,n, sincethese elements exist when they are spread from here to Alpha Centauri,but if that happens, of course, Socrates no longer exists. Heading in theother direction, Socrates can exist without just these elements, sincehe may exist when some one ofa,b,c,…,n is replaced or goes out of existence. So, inaddition to his material elements, insists Aristotle, Socrates is alsosomething else, something more (heteron ti;Met.1041b19–20). This something more isform, which is ‘notan element…but a primary cause of a thing’s being what itis’ (Met. 1041b28–30). The cause of a thing’s beingthe actual thing it is, as we have seen, is form. Hence, concludesAristotle, as the source of being and unity, form is substance.

Even if this much is granted—and to repeat, much of what hasjust been said is unavoidably controversial—many questionsremain. For example, is form best understood as universal orparticular? However that issue is to be resolved, what is therelation of form to the compound and to matter? If form issubstance, then what is the fate of these other two candidates? Are they also substances, if to a lesser degree? It seems odd toconclude that they are nothing at all, or that the compound inparticular is nothing in actuality; yet it is difficult to contend thatthey might belong to some category other than substance.

For an approach to some of these questions, see the entry onAristotle’s Metaphysics.

11. Living Beings

However these and like issues are to be resolved, given the primacy ofform as substance, it is unsurprising to find Aristotle identifyingthe soul, which he introduces as a principle or source(archê) of all life, as the form of a livingcompound. For Aristotle, in fact, all living things, and not onlyhuman beings, have souls: ‘what is ensouled is distinguishedfrom what is unensouled by living’ (DA 431a20–22;cf.DA 412a13, 423a20–6;De Part. An.687a24–690a10;Met. 1075a16–25). It isappropriate, then, to treat all ensouled bodies in hylomorphicterms:

The soul is the cause and source of the living body. Butcause andsource are meant in many ways [or arehomonymous]. Similarly, the soul is a cause in accordancewith the ways delineated, which are three: it is (i) the cause as thesource of motion [=the efficient cause], (ii) that for the sake ofwhich [=the final cause], and (iii) as the substance of ensouledbodies. That it is a cause as substance is clear, for substanceis the cause of being for all things, and for living things, being islife, and the soul is also the cause and source of life. (DA415b8–14; cf.PN 467b12–25,Phys. 255a56–10)

So, the soul and body are simply special cases of form andmatter:

soul : body :: form : matter ::actuality : potentiality

Further, the soul, as the end of the compound organism, is also thefinal cause of the body. Minimally, this is to be understood as theview that any given body is the body that it is because it isorganized around a function which serves to unify the entireorganism. In this sense, the body’s unity derives from the fact it hasa single end, or single life directionality, a state of affairs thatAristotle captures by characterizing the body as the sort of matterwhich isorganic (organikon;DA 412a28). Bythis he means that the body serves as a tool for implementing thecharacteristic life activities of the kind to which the organismbelongs (organon =tool in Greek). Taking all thistogether, Aristotle offers the view that the soul is the ‘firstactuality of a natural organic body’ (DA412b5–6), that it is a ‘substance as form of a naturalbody which has life in potentiality’ (DA412a20–1) and, again, that it ‘is a first actuality of anatural body which has life in potentiality’ (DA412a27–8).

Aristotle contends that his hylomorphism provides an attractive middleway between what he sees as the mirroring excesses of hispredecessors. In one direction, he means to reject Presocratic kindsof materialism; in the other, he opposes Platonic dualism. He givesthe Presocratics credit for identifying the material causes of life,but then faults them for failing to grasp its formal cause. Bycontrast, Plato earns praise for grasping the formal cause of life;unfortunately, as Aristotle sees things, he then proceeds to neglectthe material cause, and comes to believe that the soul can existwithout its material basis. Hylomorphism, in Aristotle’s view,captures what is right in both camps while eschewing the unwarrantedmono-dimensionality of each. To account for living organisms,Aristotle contends, the natural scientist must attend to both matterand form.

Aristotle deploys hylomorphic analyses not only to the whole organism,but to the individual faculties of the soul as well. Perceptioninvolves the reception of sensible forms without matter, and thinking,by analogy, consists in the mind’s being enformed by intelligibleforms. With each of these extensions, Aristotle both expands andtaxes his basic hylomorphism, sometimes straining its basic frameworkalmost beyond recognition.

For more detail on Aristotle’s hylomorphism in psychologicalexplanation, see the entry onAristotle’s Psychology.

12. Happiness and Political Association

Aristotle’s basic teleological framework extends to his ethicaland political theories, which he regards as complementing oneanother. He takes it as given that most people wish to leadgood lives; the question then becomes what the best life for humanbeings consists in. Because he believes that the best life for ahuman being is not a matter of subjective preference, he also believesthat people can (and, sadly, often do) choose to lead sub-optimallives. In order to avoid such unhappy eventualities, Aristotlerecommends reflection on the criteria any successful candidate for thebest life must satisfy. He proceeds to propose one kind of lifeas meeting those criteria uniquely and therefore promotes it as thesuperior form of human life. This is a life lived in accordance withreason.

When stating the general criteria for the final good for human beings,Aristotle invites his readers to review them (EN1094a22–27). This is advisable, since much of the work ofsorting through candidate lives is in fact accomplished during thehigher-order task of determining the criteria appropriate to thistask. Once these are set, it becomes relatively straightforward forAristotle to dismiss some contenders, including for instance hedonism,the perennially popular view that pleasure is the highest good forhuman beings.

According to the criteria advanced, the final good for human beingsmust: (i) be pursued for its own sake (EN 1094a1); (ii) besuch that we wish for other things for its sake (EN 1094a19);(iii) be such that we do not wish for it on account of other things(EN 1094a21); (iv) be complete (teleion), in thesense that it is always choiceworthy and always chosen for itself(EN 1097a26–33); and finally (v) be self-sufficient(autarkês), in the sense that its presence suffices tomake a life lacking in nothing (EN 1097b6–16). Plainlysome candidates for the best life fall down in the face of thesecriteria. According to Aristotle, neither the life of pleasure nor thelife of honour satisfies them all.

What does satisfy them all is happinesseudaimonia. Scholars in factdispute whethereudaimonia is best rendered as‘happiness’ or ‘flourishing’ or ‘livingwell’ or simply transliterated and left an untranslated technical term.^[24] If we have already determined thathappiness is some sort ofsubjective state, perhaps simple desire fulfillment, then‘happiness’ will indeed be an inappropriate translation:eudaimonia is achieved, according to Aristotle, by fullyrealizing our natures, by actualizing to the highest degree our humancapacities, and neither our nature nor our endowment of humancapacities is a matter of choice for us. Still, as Aristotle franklyacknowledges, people will consent without hesitation to the suggestionthat happiness is our best good—even while differing materiallyabout how they understand what happiness is. So, while seeming toagree, people in fact disagree about the human good. Consequently, itis necessary to reflect on the nature of happiness(eudaimonia):

But perhaps saying that the highest good is happiness(eudaimonia) will appear to be a platitude and what is wantedis a much clearer expression of what this is. Perhaps this would comeabout if the function (ergon) of a human being wereidentified. For just as the good, and doing well, for a flute player,a sculptor, and every sort of craftsman—and in general, forwhatever has a function and a characteristic action—seems todepend upon function, so the same seems true for a human being, ifindeed a human being has a function. Or do the carpenter and cobblerhave their functions, while a human being has none and is rathernaturally without a function (argon)? Or rather, just asthere seems to be some particular function for the eye and the handand in general for each of the parts of a human being, should one inthe same way posit a particular function for the human being inaddition to all these? Whatever might this be? For living is commoneven to plants, whereas something characteristic (idion) iswanted; so, one should set aside the life of nutrition andgrowth. Following that would be some sort of life of perception, yetthis is also common, to the horse and the bull and to everyanimal. What remains, therefore, is a life of action belonging to thekind of soul that has reason. (EN1097b22–1098a4)

In determining whateudaimonia consists in, Aristotle makes a crucialappeal to the human function (ergon), and thus to hisoverarching teleological framework.

He thinks that he can identify the human function in terms ofreason, which then provides ample grounds for characterizing the happylife as involving centrally the exercise of reason, whether practicalor theoretical. Happiness turns out to be an activity of therational soul, conducted in accordance with virtue or excellence, or,in what comes to the same thing, in rational activity executedexcellently (EN 1098a161–17). It bears noting inthis regard that Aristotle’s word for virtue,aretê, is broader than the dominant sense of the Englishword ‘virtue’, since it comprises all manner ofexcellences, thus including but extending beyond the moral virtues.Thus when he says that happiness consists in an activity in‘accordance with virtue’ (kat’ aretên;EN 1098a18), Aristotle means that it is a kind of excellentactivity, and not merely morally virtuous activity.

The suggestion that onlyexcellently executed orvirtuously performed rational activity constitutes humanhappiness provides the impetus for Aristotle’s virtueethics. Strikingly, first, he insists that the good life is a life ofactivity; nostate suffices, since we are commended andpraised for living good lives, and we are rightly commended or praisedonly for things we (do) (EN 1105b20–1106a13).Further, given that we must not only act, but act excellently orvirtuously, it falls to the ethical theorist to determine what virtueor excellence consists in with respect to the individual humanvirtues, including, for instance, courage and practicalintelligence. This is why so much of Aristotle’s ethical writingis given over to an investigation of virtue, both in general and inparticular, and extending to both practical and theoretical forms.

For more on Aristotle’s virtue-based ethics, see the entry onAristotle’s Ethics.

Aristotle concludes his discussion of human happiness in hisNicomachean Ethics by introducing political theory as acontinuation and completion of ethical theory. Ethicaltheory characterizes the best form of human life; political theorycharacterizes the forms of social organization best suited to itsrealization (EN 1181b12–23).

The basic political unit for Aristotle is thepolis, which isboth astate in the sense of being an authority-wieldingmonopoly and acivil society in the sense of being a series oforganized communities with varying degrees of converginginterest. Aristotle’s political theory is markedlyunlike some later, liberal theories, in that he does not think that thepolis requires justification as a body threatening to infringeon antecedently existing human rights. Rather, he advances a formof political naturalism which treats human beings as by naturepolitical animals, not only in the weak sense of being gregariouslydisposed, nor even in the sense of their merely benefiting from mutualcommercial exchange, but in the strong sense of their flourishing ashuman beings at allonly within the framework of an organizedpolis. Thepolis ‘comes into being for the sakeof living, but it remains in existence for the sake of livingwell’ (Pol. 1252b29–30; cf. 1253a31–37).

Thepolis is thus to be judged against the goal ofpromoting human happiness. A superior form of political organizationenhances human life; an inferior form hampers and hindersit. One major question pursued in Aristotle’sPolitics is thus structured by just this question: what sortof political arrangement best meets the goal of developing andaugmenting human flourishing? Aristotle considers a fairnumber of differing forms of political organization, and sets mostaside as inimical to the goal human happiness. For example, givenhis overarching framework, he has no difficulty rejectingcontractarianism on the grounds that it treats as merely instrumentalthose forms of political activity which are in fact partiallyconstitutive of human flourishing (Pol. iii 9).

In thinking about the possible kinds of political organization,Aristotle relies on the structural observations that rulers may be one, few,or many, and that their forms of rule may be legitimate orillegitimate, as measured against the goal of promoting humanflourishing (Pol. 1279a26–31). Taken together, these factorsyield six possible forms of government, three correct and threedeviant:

The correct are differentiated from the deviant by their relativeabilities to realize the basic function of thepolis: livingwell. Given that we prize human happiness, we should, insistsAristotle, prefer forms of political association best suited to thisgoal.

Necessary to the end of enhancing human flourishing, maintainsAristotle, is the maintenance of a suitable level of distributivejustice. Accordingly, he arrives at his classification of betterand worse governments partly by considerations of distributivejustice. He contends, in a manner directly analogous to hisattitude towardseudaimonia, that everyone will find it easyto agree to the proposition that we should prefer a just state to anunjust state, and even to the formal proposal that the distribution ofjustice requires treating equal claims similarly and unequal claimsdissimilarly. Still, here too people will differ about whatconstitutes an equal or an unequal claim or, more generally, an equalor an unequal person. A democrat will presume that all citizensare equal, whereas an aristocrat will maintain that the best citizensare, quite obviously, superior to the inferior. Accordingly, thedemocrat will expect the formal constraint of justice to yield equaldistribution to all, whereas the aristocrat will take for granted thatthe best citizens are entitled to more than the worst.

When sorting through these claims, Aristotle relies upon his ownaccount of distributive justice, as advanced inNicomacheanEthics v 3. That account is deeply meritocratic. Heaccordingly disparages oligarchs, who suppose that justice requirespreferential claims for the rich, but also democrats, who contend thatthe state must boost liberty across all citizens irrespective ofmerit. The bestpolis has neither function: its goal isto enhance human flourishing, an end to which liberty is at bestinstrumental, and not something to be pursued for its own sake.

Still, we should also proceed with a sober eye on what is in factpossible for human beings, given our deep and abiding acquisitionalpropensities. Given these tendencies, it turns out that althoughdeviant, democracy may yet play a central role in the sort of mixedconstitution which emerges as the best form of political organizationavailable to us. Inferior though it is to polity (that is, ruleby the many serving the goal of human flourishing), and especially toaristocracy (government by the best humans, thearistoi, alsodedicated to the goal of human flourishing), democracy, as the bestamongst the deviant forms of government, may also be the most we canrealistically hope to achieve.

For an in-depth discussion of Aristotle’s political theory,including his political naturalism, see the entry onAristotle’s Politics.

13. Rhetoric and the Arts

Aristotle regards rhetoric and the arts as belonging to the productivesciences. As a family, these differ from the practical sciencesof ethics and politics, which concern human conduct, and from thetheoretical sciences, which aim at truth for its own sake. Because they are concerned with the creation of human products broadlyconceived, the productive sciences include activities with obvious,artefactual products like ships and buildings, but also agriculture andmedicine, and even, more nebulously, rhetoric, which aims at theproduction of persuasive speech (Rhet. 1355b26; cf.Top. 149b5), and tragedy, which aims atthe production of edifying drama (Poet.1448b16–17). If we bear in mind that Aristotleapproaches all these activities within the broader context of histeleological explanatory framework, then at least some of the highlypolemicized interpretative difficulties which have grown up around hisworks in this area, particularly thePoetics, may be sharplydelimited.

One such controversy centers on the question of whetherAristotle’sRhetoric andPoetics are primarilydescriptive or prescriptive works.^[25] To the degree that they are indeedprescriptive, one may wonder whether Aristotle has presumed in thesetreatises to dictate to figures of the stature of Sophocles andEuripides how best to pursue their crafts. To someextent—but only to some extent—it may seem that hedoes. There are, at any rate, clearly prescriptive elements inboth these texts. Still, he does not arrive at theserecommendationsa priori. Rather, it is plain thatAristotle has collected the best works of forensic speech and tragedyavailable to him, and has studied them to discern their more and lesssuccessful features. In proceeding in this way, he aims tocapture and codify what is best in both rhetorical practice andtragedy, in each case relative to its appropriate productive goal.

The general goal of rhetoric is clear. Rhetoric, says Aristotle,‘is the power to see, in each case, the possible ways topersuade’ (Rhet. 1355b26). Different contexts, however,require different techniques. Thus, suggests Aristotle, speakers willusually find themselves in one of three contexts where persuasion isparamount: deliberative (Rhet. i 4–8), epideictic(Rhet. i 9), and judicial (Rhet. i 10–14). In eachof these contexts, speakers will have at their disposal three mainavenues of persuasion: the character of the speaker, the emotionalconstitution of the audience, and the general argument(logos) of the speech itself (Rhet. i 3). Rhetoricthus examines techniques of persuasion pursuant to each of theseareas.

When discussing these techniques, Aristotle draws heavily upon topicstreated in his logical, ethical, and psychological writings. In thisway, theRhetoric illuminates Aristotle’s writings in thesecomparatively theoretical areas by developing in concrete ways topicstreated more abstractly elsewhere. For example, because a successfulpersuasive speech proceeds alert to the emotional state of theaudience on the occasion of its delivery, Aristotle’sRhetoric contains some of his most nuanced and specifictreatments of the emotions. Heading in anotherdirection, a close reading of theRhetoric reveals thatAristotle treats the art of persuasion as closely akin to dialectic(see §4.3 above). Like dialectic, rhetoric trades intechniques that are not scientific in the strict sense (see §4.2above), and though its goal is persuasion, it reaches its end best ifit recognizes that people naturally find proofs and well-turnedarguments persuasive (Rhet. 1354a1, 1356a25,1356a30). Accordingly, rhetoric, again like dialectic,begins with credible opinions (endoxa), though mainly of thepopular variety rather than those endorsed most readily by the wise(Top. 100a29–35; 104a8–20;Rhet.1356b34). Finally, rhetoric proceeds from such opinions toconclusions which the audience will understand to follow by cogentpatterns of inference (Rhet. 1354a12–18,1355a5–21). For this reason, too, the rhetorician will dowell understand the patterns of human reasoning.

For more on Aristotle’s rhetoric, see the entry onAristotle’s Rhetoric.

By highlighting and refining techniques for successful speech, theRhetoric is plainly prescriptive—but only relative tothe goal of persuasion. It does not, however, select itsown goal or in any way dictate the end of persuasive speech: rather,the end of rhetoric is given by the nature of the craft itself. In this sense, theRhetoric is like both theNicomacheanEthics and thePolitics in bearing the stamp ofAristotle’s broad and encompassing teleology.

The same holds true of thePoetics, but in this case theend is not easily or uncontroversially articulated. It is oftenassumed that the goal of tragedy iscatharsis—thepurification or purgation of the emotions aroused in a tragicperformance. Despite its prevalence, as an interpretation of whatAristotle actually says in thePoetics this understanding isunderdetermined at best. When defining tragedy in a general way,Aristotle claims:

Tragedy, then, is an imitation of an action that is serious andcomplete, and which has some greatness about it. It imitates in wordswith pleasant accompaniments, each type belonging separately to thedifferent parts of the work. It imitates people performing actions anddoes not rely on narration. It achieves, through pity and fear, thecatharsis of these sorts of feelings. (Poet.1449b21–29)

Although he has been represented in countless works of scholarshipas contending that tragedyis for the sake of catharsis,Aristotle is in fact far more circumspect. While he does contendthat tragedy will effect or accomplish catharsis, in so speaking hedoes not use language which clearly implies that catharsis is in itselfthe function of tragedy. Although a good blender will achieve ablade speed of 36,000 rotations per minute, this is not its function;rather, it achieves this speed in service of its function, namelyblending. Similarly, then, on one approach, tragedy achievescatharsis, though not because it is its function to do so. This remains so, even if it is integral to realizing its function thattragedy achieve catharsis—as it is equally integral that it makesus of imitation (mimêsis), and does so by using wordsalong with pleasant accompaniments (namely, rhythm, harmony, and song;Poet. 1447b27).

Unfortunately, Aristotle is not completely forthcoming on the questionof the function of tragedy. One clue towards his attitudecomes from a passage in which he differentiates tragedy from historicalwriting:

The poet and the historian differ not in that one writes in meter andthe other not; for one could put the writings of Herodotus into verseand they would be history none the less, with or without meter. Thedifference resides in this: the one speaks of what has happened, andthe other of what might be. Accordingly, poetry is more philosophicaland more momentous than history. The poet speaks more of theuniversal, while the historian speaks of particulars. It is universalthat when certain things turn out a certain way someone will in alllikelihood or of necessity act or speak in a certain way—whichis what the poet, though attaching particular names to the situation,strives for (Poet. 1451a38–1451b10).

In characterizing poetry as more philosophical, universal, andmomentous than history, Aristotle praises poets for their ability toassay deep features of human character, to dissect the ways in whichhuman fortune engages and tests character, and to display how humanfoibles may be amplified in uncommon circumstances. We do not,however, reflect on character primarily for entertainment value. Rather, and in general, Aristotle thinks of the goal of tragedy inbroadly intellectualist terms: the function of tragedy is‘learning, that is, figuring out what each thing is’(Poet. 1448b16–17). In Aristotle’s view,tragedy teaches us about ourselves.

That said, catharsis is undoubtedly a key concept in Aristotle’sPoetics, one which, along with imitation(mimêsis), has generated enormous controversy.^[26] Thesecontroversies center around three poles of interpretation: thesubject of catharsis, thematter of the catharsis,and thenature of catharsis. To illustrate what ismeant: on a naïve understanding of catharsis—which maybe correct despite its naïveté—theaudience(the subject) undergoes catharsis by having theemotions (thematter) of pity and fear it experiencespurged (thenature). By varying just these three possibilities, scholars haveproduced a variety of interpretations—that it is the actors oreven the plot of the tragedy which are the subjects of catharsis, thatthe purification is cognitive or structural rather than emotional, andthat catharsis is purification rather than purgation. On thislast contrast, just as we might purify blood by filtering it, ratherthan purging the body of blood by letting it, so we might refine ouremotions, by cleansing them of their more unhealthy elements, ratherthan ridding ourselves of the emotions by purging themaltogether. The difference is considerable, since on one view theemotions are regarded as in themselves destructive and so to be purged,while on the other, the emotions may be perfectly healthy, even though,like other psychological states, they may be improved byrefinement. The immediate context of thePoetics doesnot by itself settle these disputes conclusively.

Aristotle says comparatively more about the second main concept of thePoetics, imitation (mimêsis). Althoughless controversial than catharsis, Aristotle’s conception ofmimêsis has also been debated.^[27] Aristotle thinks thatimitation is a deeply ingrained human proclivity. Like politicalassociation, he contends,mimêsis isnatural. We engage in imitation from an early age,already in language learning by aping competent speakers as we learn,and then also later, in the acquisition of character by treating othersas role models. In both these ways, we imitate because we learnand grow by imitation, and for humans, learning is both natural and adelight (Poet. 1148b4–24). This same tendency, inmore sophisticated and complex ways, leads us into the practice ofdrama. As we engage in more advanced forms ofmimêsis, imitation gives way torepresentationanddepiction, where we need not be regarded as attempting tocopy anyone or anything in any narrow sense of the term. For tragedy does not set out merely to copy what is the case, butrather, as we have seen in Aristotle’s differentiation of tragedyfrom history, to speak of what might be, to engage universal themes ina philosophical manner, and to enlighten an audience by theirdepiction. So, althoughmimêsis is at root simpleimitation, as it comes to serve the goals of tragedy, it grows moresophisticated and powerful, especially in the hands of those poets ableto deploy it to good effect.

14. Aristotle’s Legacy

Aristotle’s influence is difficult to overestimate. Afterhis death, his school, the Lyceum, carried on for some period of time,though precisely how long is unclear. In the century immediatelyafter his death, Aristotle’s works seem to have fallen out ofcirculation; they reappear in the first century B.C.E., after which timethey began to be disseminated, at first narrowly, but then much morebroadly. They eventually came to form the backbone of some sevencenturies of philosophy, in the form of thecommentary tradition, much of it original philosophy carried on ina broadly Aristotelian framework. They also played a verysignificant, if subordinate role, in the Neoplatonic philosophy ofPlotinus andPorphyry. Thereafter, from the sixth through the twelfth centuries, although thebulk of Aristotle’s writings were lost to the West, they receivedextensive consideration inByzantine Philosophy, and in Arabic Philosophy, where Aristotle was soprominent that be became known simply as The First Teacher (seethe entry on theinfluence of Arabic and Islamic philosophy on the Latin West). In this tradition, the notably rigorous and illuminating commentaries ofAvicenna and Averroes interpreted and developed Aristotle’s viewsin striking ways. These commentaries in turn proved exceedinglyinfluential in the earliest reception of the Aristotelian corpus intothe Latin West in the twelfth century.

Among Aristotle’s greatest exponents during the early period ofhis reintroduction to the West,Albertus Magnus, and above all his studentThomas Aquinas, sought to reconcile Aristotle’s philosophy with Christianthought. Some Aristotelians disdain Aquinas as bastardizing Aristotle,while some Christians disown Aquinas as pandering to paganphilosophy. Many others in both camps take a much more positive view,seeing Thomism as a brilliant synthesis of two towering traditions;arguably, the incisive commentaries written by Aquinas towards the endof his life aim not so much at synthesis as straightforward exegesisand exposition, and in these respects they have few equals in anyperiod of philosophy. Partly due to the attention of Aquinas, but formany other reasons as well, Aristotelian philosophy set the frameworkfor the Christian philosophy of the twelfth through the sixteenthcenturies, though, of course, that rich period contains a broad rangeof philosophical activity, some more and some less in sympathy withAristotelian themes. To see the extent of Aristotle’s influence, however,it is necessary only to recall that the two concepts forming theso-calledbinarium famosissimum (“the most famous pair”) of thatperiod, namely universal hylomorphism and the doctrine of the pluralityof forms, found their first formulations in Aristotle’stexts.

Interest in Aristotle continued unabated throughout the renaissance inthe form ofRenaissance Aristotelianism. The dominant figures of this period overlapwith the last flowerings of Medieval Aristotelian Scholasticism, whichreached a rich and highly influential close in the figure ofSuárez, whose life in turn overlaps with Descartes. Fromthe end of late Scholasticism, the study of Aristotle has undergonevarious periods of relative neglect and intense interest, but has beencarried forward unabated down to the present day.

Today, philosophers of various stripes continue to look to Aristotlefor guidance and inspiration in many different areas, ranging from thephilosophy of mind to theories of the infinite, though perhapsAristotle’s influence is seen most overtly and avowedly in theresurgence ofvirtue ethics which began in the last half of the twentieth century. It seems safe at this stage to predict that Aristotle’s statureis unlikely to diminish anytime in the foreseeable future. If it is anyindication of the direction of things to come, a quick search of thepresent Encyclopedia turns up more citations to ‘Aristotle’ and‘Aristotelianism’ than to any other philosopher orphilosophical movement. Only Plato comes close.

Bibliography

This bibliography limits itself to translations general works onAristotle, and works cited in this entry. Please see thesubjective-specific bibliographies in the entries under General andSpecial Topics for references to works pertinent to more specificareas of Aristotle’s philosophy.

A. Translations

The Standard English Translation of Aristotle’s Complete Worksinto English is:

• Barnes, J., ed.The Complete Works of Aristotle, VolumesI and II, Princeton: Princeton University Press, 1984.

An excellent translation of selections of Aristotle’s worksis:

• Irwin, T. and Fine., G.,Aristotle: Selections, Translated with Introduction, Notes, andGlossary, Indianapolis: Hackett, 1995.

B. Translations with Commentaries

The best set of English translations with commentaries is theClarendon Aristotle Series:

• Ackrill, J.,Categories and De Interpretatione,translated with notes, Oxford: Oxford University Press, 1963.
• Annas, J.,Metaphysics Books M and N, translated with acommentary, Oxford: Oxford University Press, 1988.
• Balme, D.,De Partibus Animalium I and De GenerationeAnimalium I, (with passages from Book II. 1–3), translated withan introduction and notes, Oxford: Oxford University Press, 1992.
• Barnes, J.,Posterior Analytics, second edition,translated with a commentary, Oxford: Oxford University Press,1994.
• Bostock, D.,Metaphysics Books Z and H, translated with acommentary, Oxford: Oxford University Press, 1994.
• Charlton, W.,Physics Books I and II, translated withintroduction, commentary, Note on Recent Work, and revisedBibliography, Oxford: Oxford University Press, 1984.
• Graham, D.,Physics, Book VIII, translated with acommentary, Oxford: Oxford University Press, 1999.
• Hamlyn, D.,De Anima II and III, with Passages from BookI, translated with a commentary, and with a review of recent workby Christopher Shields, Oxford: Oxford University Press, 1999.
• Hussey, E.,Physics Books III and IV, translated with anintroduction and notes, Oxford: Oxford University Press, 1983; newimpression with supplementary material, 1993.
• Judson, L.,Metaphysics Book Λ, edited, translatedwith an introduction and commentary, Oxford: Oxford University Press,2019.
• Keyt, D.,Politics, Books V and VI Animals, translatedwith a commentary, Oxford: Oxford University Press, 1999.
• Kirwan, C.,Metaphysics: Books gamma, delta, andepsilon, second edition, translated with notes,Oxford: Oxford University Press, 1993.
• Kraut, R.,Politics Books VII and VIII, translated with acommentary, Oxford: Oxford University Press, 1998.
• Lennox, J.,On the Parts of Animals, translated with acommentary, Oxford: Oxford University Press, 2002.
• Madigan, A.,Aristotle: Metaphysics Books B and K 1–2,translated with a commentary, Oxford: Oxford University Press, 2000.
• Makin, S.,Metaphysics Theta, translated with anintroduction and commentary, Oxford: Oxford University Press, 2006.
• Pakaluk, M.,Nicomachean Ethics, Books VIII and IX,translated with a commentary, Oxford: Oxford University Press, 1999.
• Robinson, R.,Politics: Books III and IV, translated witha commentary by Richard Robinson; with a supplementary essay by DavidKeyt, Oxford: Oxford University Press, 1996.
• Saunders, T.,Politics: Books I and II, translated with acommentary, Oxford: Oxford University Press, 1996.
• Shields, Christopher,De Anima, translated with anintroduction and commentary, Oxford: Oxford University Press, 2015.
• Smith, R.,Topics Books I and VIII, Withexcerpts from related texts, translated with a commentary, Oxford:Oxford University Press, 2009.
• Striker, G.,Prior Analytics,translated with a commentary, Oxford: Oxford University Press,1997.
• Taylor, C.,Nicomachean Ethics, Books II-IV, translatedwith an introduction and commentary, Oxford: Oxford University Press,2006.
• Williams, C.,De Generatione et Corruptione, translatedwith a commentary, Oxford: Oxford University Press, 1983.
• Woods, M.,Eudemian Ethics Books I, II, and VIII, secondedition, edited, and translated with a commentary, Oxford: OxfordUniversity Press, 1992.

C. General Works

1. Comprehensive Introductions to Aristotle

• Ackrill, J.,Aristotle the Philosopher, Oxford: OxfordUniversity Press, 1981.
• Jaeger, W.,Aristotle: Fundamentals of the History of hisDevelopment, Oxford: Oxford University Press, 1934.
• Lear, J.,Aristotle: the Desire to Understand, Cambridge:Cambridge University Press, 1988.
• Ross, W. D.,Aristotle, London: Methuen and Co., 1923.
• Shields, C.,Aristotle 2nd edition, London: Routledge, 2014.

2. General Guide Books to Aristotle

• Barnes, J.,The Cambridge Companion to Aristotle,Cambridge: Cambridge University Press, 1995.
• Anagnostopoulos, G.,The Blackwell Guide to Aristotle,Oxford: Blackwell, 2007.
• Shields, C.,The Oxford Handbook on Aristotle, Oxford:Oxford University Press, 2012.

3. Aristotle’s Life

• Natali, C.,Aristotle: His Life and School, D. Hutchinson(ed.), Princeton: Princeton University Press, 2013.

D. Bibliography of Works Cited

• Annas, J., 1982, ‘Aristotle on inefficient causes,’Philosophical Quarterly, 32: 311–326.
• Bakker, Paul J. J. M., 2007, ‘Natural Philosophy,Metaphysics, or Something in Between: Agostino Nifo, PietroPompanazzi, and Marcantonio Genua on the Nature and Place of theScience of Soul,’ in J. J. M. Bakker and JohannesM. M. H. Thijssen (eds.),Mind, Cognition, and Representation: TheTradition of Commentaries on Aristotle’s De Anima, London:Ashgate, pp. 151–177.
• Barnes, Jonathan, 1994,Posterior Analytics,second edition, translated with a commentary, Oxford: Clarendon Press.
• Biondi, Paolo C. (ed. and trans.), (2004),Aristotle: PosteriorAnalytics ii 19, Paris: Librairie-Philosophique-J-Vrin.
• Bostock, David, 1980/2006, ‘Aristotle’s Account ofTime,‘ inSpace, Time, Matter, and Form: Essays onAristotle’s Physics, Oxford: Oxford University Press,pp. 135–157.
• Charles, David, 2001, “Teleological Causation in thePhysics,” in L. Judson (ed.),Aristotle’sPhysics: A Collection of Essays, Oxford: Oxford University Press,pp. 101–128.
• Cleary, John, 1994, ‘Phainomena in Aristotle’sPhilosophic Method,’International Journal of PhilosophicalStudies, 2: 61–97.
• Coope, Ursula, 2005,Time for Aristotle: Physics IV 10–14,Oxford: Oxford University Press.
• Duarte, Shane, 2014, ‘Aristotle’s Theology and itsRelation to the Science of Beingqua Being,’Apeiron, 40: 267–318
• Frede, M., 1980, ‘The Original Notion of Cause,’ in M.Schofield, M. Burnyeat, and J. Barnes (ed.),Doubt andDogmatism, Oxford: Oxford University Press, pp. 217–249.
• Furley, D. J., ‘What Kind of Cause is Aristotle’s FinalCause?,’ in M. Frede and G. Stricker (eds.),Rationality inGreek Thought, Oxford: Oxford University Press, 1999,pp. 59–79.
• Gill, M. L., ‘Aristotle’sMetaphysicsReconsidered,’Journal of the History of Philosophy, 43(2005): 223–251.
• Gotthelf, A., 1987, ‘Aristotle’s Conception of FinalCausality,’ in A. Gotthelf and J. G. Lennox (eds.),Philosophical Issues in Aristotle’s Biology, Cambridge:Cambridge University Press, pp. 204–242.
• Grote, George, 1880,Aristotle, London: ThoemmesContinuum.
• Halliwell, Stephen, 1986,Aristotle’s Poetics,Chapel Hill: University of North Carolina Press.
• Hocutt, M., 1974, ‘Aristotle’s Four Becauses.’Philosophy, 49: 385–399.
• Irwin, Terence, 1981, ‘Homonymy in Aristotle,’Review of Metaphysics, 34: 523–544.
• –––, 1988,Aristotle’s FirstPrinciples, Oxford: Oxford University Press.
• Johnson, Monte Ransom, 2005,Aristotle on Teleology,Oxford: Oxford University Press.
• Kraut, Richard, 1979, ‘Two Conceptions of Happiness,Philosophical Review, 88: 167–197.
• Lewis, Frank A., 2004, ‘Aristotle on the Homonymy ofBeing,’Philosophy and Phenomenological Research, 68:1–36.
• Loux, Michael, 1973, ‘Aristotle on theTranscendentals,’Phronesis, 18: 225–239.
• Moravcsik, J., 1975, ‘“Aitia” asgenerative factor in Aristotle’s philosophy,’Dialogue, 14: 622–638.
• Owen, G. E. L., 1960, ‘Logic and Metaphysics in Some EarlierWorks of Aristotle,’ in I. During and G. E. L. Owen (eds.),Plato and Aristotle in the Mid-Fourth Century, Göteborg:Almquist and Wiksell, pp. 163–190.
• –––, 1961/1986, ‘Tithenai taphainomena,’Logic, Science and Dialectic, London:Duckworth, pp. 239–251.
• Owens, Joseph, 1978,The Doctrine of Being in theAristotelian Metaphysics, 3^rd edition, Toronto: ThePontifical Institute of Mediaeval Studies.
• Patzig, Gunther, 1979, ‘Theology and Ontology inAristotle’s Metaphysics, in J. Barnes, M. Schofied, and R. Sorabji(eds.),Articles on Aristotle, Volume 3: Metaphysics, London:Duckworth, pp. 33–49.
• Pellegrin, Pierre, 1996/2003, ‘Aristotle,’ in J.Brunschwig and G. E. R. Lloyd (eds.),A Guide to Greek Thought,Cambridge, MA: Harvard University Press, pp. 32–53.
• Ross, W. D., 1923,Aristotle, London: Methuen and Co.
• Sauvé Meyer, S., 1992, ‘Aristotle, Teleology, andReduction,’Philosophical Review, 101: 791–825.
• Shields, Christopher, 1999,Order in Multiplicity: Homonymy inthe Philosophy of Aristotle, Oxford: Oxford University Press.
• –––, 2014,Aristotle, London: Routledge.
• Shute, Richard, 1888,On the Process by which the AristotelianWritings Arrived at their Present Form, Oxford: Oxford UniversityPress.
• Ward, Julie K., 2008,Aristotle on Homonymy, Cambridge:Cambridge University Press.
• Zeller, Eduard, 1883/1955,Outlines of the History of GreekPhilosophy, rev. by W. Nestle, trans. L. Palmer, London:Routledge.

Academic Tools

	How to cite this entry.
	Preview the PDF version of this entry at theFriends of the SEP Society.
	Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO).
	Enhanced bibliography for this entryatPhilPapers, with links to its database.

Other Internet Resources

• Aristotle, maintained by Marc Cohen (Philosophy/University of Washington).
• Aristotle,a podcast in theHistory of Philosophy without Gaps project, overseen by Peter Adamson.

Related Entries

Arabic and Islamic Philosophy, historical and methodological topics in: influence of Arabic and Islamic Philosophy on the Latin West |Aristotle, commentators on |Aristotle, General Topics: aesthetics |Aristotle, General Topics: biology |Aristotle, General Topics: categories |Aristotle, General Topics: ethics |Aristotle, General Topics: logic |Aristotle, General Topics: metaphysics |Aristotle, General Topics: political theory |Aristotle, General Topics: psychology |Aristotle, General Topics: rhetoric |Aristotle, Special Topics: causality |Aristotle, Special Topics: mathematics |Aristotle, Special Topics: natural philosophy |Aristotle, Special Topics: on non-contradiction |Aristotle, Special Topics: textual transmission of Aristotelian corpus |essential vs. accidental properties |form vs. matter |happiness |Hegel, Georg Wilhelm Friedrich: dialectics |human nature |substance

Acknowledgments

I thank Thomas Ainsworth, John Cooper, Fred Miller, Nathanael Stein,Edward Zalta, and an anonymous reader for SEP for their valuableassistance in the preparation of this entry. Additionally, I thankthe twenty or so undergraduates in Cornell and Oxford Universities whoprovided instructive feedback on earlier drafts.