The expression “continental rationalism” refers to a setof views more or less shared by a number of philosophers active on theEuropean continent during the latter two thirds of the seventeenthcentury and the beginning of the eighteenth. Rationalism is most oftencharacterized as an epistemological position. On this view, to be arationalist requires at least one of the following: (1) a privilegingof reason and intuition over sensation and experience, (2) regardingall or most ideas as innate rather than adventitious, (3) an emphasison certain rather than merely probable knowledge as the goal ofenquiry. While all of the continental rationalists meet one or more ofthese criteria, this is arguably the consequence of a deeper tie thatbinds them together—that is, a metaphysical commitment to thereality of substance, and, in particular, to substance as anunderlying principle of unity.

• 1. Introduction: Rationalism and Substance
• 2. Descartes and His Critics
• 3. Malebranche and Cavendish
• 4. Spinoza
• 5. Leibniz and Conway
• 6. Beyond Continental Rationalism: Other Voices
• Bibliography
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1. Introduction: Rationalism and Substance

The seventeenth and early eighteenth centuries saw the heyday ofmetaphysical system-building, but the expression“continental rationalism” primarily connotes rather a setofepistemological views. By contrast to British empiricism,which traces all knowledge to sensory experience, these viewsemphasize a reliance on reason (ratio in Latin, hencerationalism), the resources of which are taken to be sufficient insome sense for what we know. Thus, a signature doctrine of rationalismis the doctrine of innate ideas, according to which the mind has builtinto it not just the structure of knowledge but even itscontent. Nonetheless, among the philosophers comprising the extensionof the expression, metaphysical issues, particularly the ontology ofsubstance, occupy the central place. Certainly, this is true ofLeibniz and Spinoza, but also of Malebranche and other Cartesians, andeven of Descartes on some plausible understandings of him.

To understand the relationship between rationalism’smetaphysical and epistemological commitments, it is helpful to recallPlato’s divided line, which establishes a parallel betweenobjects known and the means by which they are known. In fact, theorder of objects, theordo essendi ranging in importance downfrom the Good to other forms, to individual things, and to images, andthe order of knowing, theordo cognoscendi, ranging fromintuition of various sorts down to sensory experience, is itself to befound in various versions among the later rationalists. The importantpoint, in any case, is that, for the continental rationalists as forPlato, the epistemological distinctions are grounded in ontologicaldistinctions. Or, to put it in terms that reflect rationalist thinkingon a number of issues, there is only a distinction of reason betweenthe two orders. The orders of being and knowing are not reallydistinct; they differ only in our ways of thinking about them.

There is a good explanation of the close connection seen by therationalists between the epistemological and ontological orders, onethat also accounts for their notable reliance on reason. It derivesfrom their answer to what Leibniz called the grand metaphysicalquestion: why is there something rather than nothing at all? There issomething because there must be something; there cannot be nothing (andthis way of putting it shows the ultimate debt of the rationalists to atradition that goes back to Parmenides). Reality, or at least some partof it, has necessary existence, and that necessity is something likelogical necessity. With this answer, a whole philosophical outlookfalls into place. First of all, any significant role for sensoryexperience falls away, since what exists can be knowna prioriby logic alone. Causal connections tend to be viewed as logicalconnections; a principle of sufficient reason falls out which tends tobe read as a matter of logical deduction. One result is that there isan impulse toward monism: if the ultimate cause must exist, then thatfor which it is the sufficient reason must also exist, and just how thetwo can be distinguished becomes problematic (again, the Parmenideanantecedent is clear).

This outlook was not articulated as such by any rationalist except,perhaps, Spinoza—indeed most were concerned to avoid suchconsequences of their views. But the outlook does capture theintuitions behind the metaphysical systems they elaborated. And itcertainly draws the contrast between them and the empiricists, whotended towardtychism, the view that the world is largely, oreven entirely, a product of chance. On the empiricist account, theuniverse consists of many independent individuals, which, if they areconnected, are so only accidentally, reducing causation to nothingmore than a matter of constant conjunction. (This physical,metaphysical, and logical atomism is in the tradition of Democritus,Epicurus, and Lucretius.) Under such circumstances, only experience ofthe world can provide knowledge of it.

The early modern period of philosophy, including continentalrationalism, is generally supposed to have been driven by the newscience to a radical departure from the Aristotelianism of the latemedieval or renaissance period immediately preceding it. (But seeGoldstone’s 1998 problematization of the very idea of earlymodernity, and of the view that the period was launched by the NewScience.) The mechanization and mathematization of the world demandedby the inertial physics of a moving Earth led to a revolutionaryphilosophy better described, at least in its rationalist version, asPlatonic, or even Pythagorean. Even so, Aristotelian concepts andterminology persisted. Both were appropriated and deployed to dealwith the new problems. The principal Aristotelian concept taken overby the rationalists was the concept of substance.

Aristotle’s termousia is usually translated as“substance”. What exactly Aristotle meant by the term is athorny matter, much debated in the literature. His account ofsubstance in theCategories holds individual things, which heterms “proper substances”, to be paradigmatic ofsubstance. On this account, substance is best understood by analogywith a grammatical subject—it takes a predicate, and is notpredicable of anything further. Thus, while animal is predicable ofhorse, and horse of Bucephalus, Bucephalus stands by himself,impredicable of, and hence, numerically different from anythingelse. Much of Aristotle’s account intheMetaphysics—written years later—seems toaccord with this. However,Metaphysics (1017b10–26)complicates the story. Aristotle there describes four uses of theterm. He concludes by reducing these to two broad senses—(1)substance ashypokeimenon, the ultimate substratum, which isnot predicated of anything further; and (2) substance as form—that which makes each thing the kind of thing that it is. Indicationswithin the text suggest that, by the time that he was giving thelectures that are collected in theMetaphysics, Aristotle regarded not individual things but thematter of which these individual things are formed as the ultimatesubject of predication. On this conception, there is some sense inwhich Bucephalus is himself predicable of matter. Thus, while thesubstance of theCategories serves as a principle ofindividuation, the substance of theMetaphysics is morecomplicated, serving both to individuate Bucephalus and Seabiscuit andto capture the connection or sameness that holds between them.

That substance should be called upon to account for both differenceand sameness in the world indicates an inherent tension in theconcept. Certainly, the two senses of the term‘substance’ were in tension during the seventeenthcentury. The momentum of rationalist argument was to resolve thetension by folding the first sense into the second: there is no realdifferentiation in the world, only the appearance ofdifference. Seventeenth century rationalists assigned to substancethree roles of connection. Substance was taken (1) to connectattributes as attributes of the same thingat a time (a givenshape and a given size as the shape and size of the same thing), (2)to connect themover time (the later shape and size, perhapsdifferent from the earlier, as nonetheless the shape and size of thevery same thing), and (3) to connect them as somehow related to thething as a certain kind of thing (for the Cartesians, shape and sizewould indicate the thing to be of the kind “extended”).However, Spinoza alone among the continental rationalists fullyembraced the conception of substance as a fundamental connectionbetween things. The other members of the movement struggled to retaina notion of substance as individuator, but did so with varying degreesof success.

2. Descartes and His Critics

The rationalism of the most famous of the rationalists is problematicon two counts. First, Descartes is known as the father of modernphilosophy precisely because he initiated the so-calledepistemological turn that is with us still. Since Descartes,philosophy has been especially concerned with the theory of knowledge,both in itself and as it affects other areas of philosophy. Ethics,for example, has often been concerned with how the good might be knownrather than with what the good might be. With his fundamentalobjective of achieving certainty for his beliefs, Descartes has thusbeen principally responsible for the incomplete characterization ofrationalism as not just etymologically but essentially connected tothe claims of reason. While Descartes certainly sought to justify theclaims of reason and relied upon them, even for him there arecorresponding ontological views that are no less important to hissystem.

The second problematic aspect of Descartes’s rationalism is moredifficult to resolve. Descartes was a radical voluntarist who thoughtthat all truth, including what we take to be necessary truth, dependson the will of God. Care needs to be taken in how this view isexpressed, for Descartes did not hold simply that what we take to benecessary in fact is contingent. He held that actually necessary truthdepends on God’s unconstrained will, such that even propositionsthat are logically contradictory might have been simultaneouslytrue. Reason itself thus seems no longer reliable, and experiencewould seem to be the only way of determining which of the worlds evenbeyond logic such a powerful and unconstrained God has created. Notmany of the rationalists, even among the Cartesians, followedDescartes in this radical voluntarism, and some in recent times haveseen the view as ultimately incoherent. Even so, Descartes seems tohave taken the view as the basis at least of his physics, and perhapsof his whole system. Indeed, on some accounts, it was this doctrine ofcreated truth that enabled Descartes to frame the most radical doubthitherto conceived, when in theMeditations he entertainedthe possibility that he was always deceived by a mendacious deity,even when considering what appeared to him most obviously true, towit, the existence of the “simplest things” that are thesubjects of arithmetic and geometry. (Against this view, MargaretWilson (1982, 105–114), observes that, in Meditation 1, God needonly have the power to deceive me about the eternal truths, not tocreate them.) While a doubt (and a doctrine) this radical might leadone to despair of ever achieving sure knowledge, for Descartes, it wasthe catalyst for his discovery of thecogito, and with it,his first indubitable truth—the truth of his own existence.

At every stage of Descartes’s argument intheMeditations, there are ontological implications: themind’s independence of sensory perceptions (perceptions whosereliability is ultimately upset by the possibility that he isdreaming), the literally unimaginable sort of thing that a physicalobject such as a piece of wax must be, the existence of a veraciousGod, who provides a guarantee for the reliability of reason, andfinally the existence of a physical world consisting of extendedthings. Arnauld immediately suggested to Descartes that his argumentcontained a circle: we can rely on reason only if we know that Godexists, but we know that God exists only by relying on reason. Thus,Descartes has established the certainty only of his own existence, butnothing beyond that. Descartes thought that he had a response to thiscriticism, but whether he did, and how cogent it is as a rebuttal,have been perennial questions of debate among Descartes scholars. Oneway to understand Descartes’s procedure is that while he doesnot claim to prove even that he exists, he does claim to show that itis unreasonable to think otherwise. That is, he shows that theargument of the skeptic fails because the consistent application ofreason leads to the view not that reason is unreliable, but preciselythe opposite. The skeptic might be right, but he is unreasonable. Aparallel case in the moral realm might be brought out here. Over thecourse of an exchange with Mesland about the nature of human freedom,Descartes notes that we can, absolutely speaking, act against againstour reason and judgment. However, morally speaking, we cannot (CSM III245/AT 4:173). When explaining what he means by this, Descartessuggests that we can only act against our better judgment and reasonin the case where we take it to be a good thing to demonstrate ourfreedom by doing so. This is what Kenny has called the “freedomof perversity” (Kenny 1998). In other words, only with theattitude of perversion can we act against what we take to be best. So,as in the epistemological realm, so too in the moral realm: it isunreasonable or even perverse to deny the results of the consistentuse of reason. Descartes thus emerges at least as a bootstraprationalist—using innate reason and a disinclination toperversity to assert the truth of his own existence, which, in turn,serves as a foundation for a more extensive search aftertruth—in a way that mirrors the non-absolute status of hisnecessary truths. The rationalist connection between the orders ofbeing and knowing is thus preserved.

But what sense can be made of the doctrine of created truth? By whatkind of causality did God create the eternal (necessary) truths? Inresponse to this very question Descartes replied that God did so injust the way that He created everything else, that He is the total andefficient cause not only of the existence of created things, but alsoof their essence. The eternal truths are just this essence of createdthings. As before, Descartes did not elaborate his answer, but, onceagain, he provided enough elsewhere for us to do so. It is clear thatfor Descartes, as for many other theologically orthodox thinkers, theexistence of things results from an unconstrained exercise of God’somnipotent will to createex nihilo. What Descartes might besaying, then, is that an eternal truth or essence is also somethingthat is createdex nihilo. The eternal truths might thus beinstances of what Descartes called substance.

In thePrinciples, Descartes defined “substance”as a thing that exists such that its existence does not depend on anyother thing. He immediately added that, strictly speaking, the termapplies only to God, who, as uncreated, alone depends on nothing elseto exist. However, he allowed that in an extended sense it applies tothings that depend only on God’s creation and continuingconservation. These created substances are really distinct from othersubstances insofar as they are conceivable apart from each other. Theydo not require a subject of inherence, and are thus ontologically, ifnot causally, independent. These created substances are distinguishedfrom other things, such as qualities, which not only depend on Godcausally, but also depend ontologically on other things, ultimately oncreated substances, as subjects of inherence. In this sense, a createdsubstance for Descartes is like thehypokeimenon ofAristotle, playing both its roles, as individuator and bearer ofqualities. However, with his definition of the real distinction, hebuilt in an unintended tendency toward monism—a tendency thatSpinoza exploited. For Descartes, one thing is really distinct fromanother just in case it can be conceived apart from that other. But,if this test of independence is applied to causal relations, itproduces the result that there is but one substance, God.

What types of things counted as created substances for Descartes?Clearly, he takes an individual mind to be a created substance. If amind did not have this status, then Descartes’s argument for itsimmortality, that it can be conceived apart from all else except God,anda fortiori from the body, would collapse. Beyond minds,however, an ambiguity appears. Although there are texts in whichDescartes speaks of individual things like a piece of wax assubstances, there are others—most famously, the Synopsis totheMeditations—that indicate that there is but asingle extended substance, of which individual things are themodes. At a minimum, there is an asymmetry in his treatment of mindsand material things, perhaps reflecting the tension betweenahypokeimenon, accounting for difference, and the othersense ofousia, accounting for sameness. To say that Peterand Paul are substances is to say that their minds are numericallydistinct; but to say that a piece of wax and a piece of wood aresubstances might be to say that they are both extended things.

However many instances of each kind there might be, there is adualism of two kinds of substance, according to Descartes: thinkingthings, or minds, and extended things, or bodies. This dualismgenerated two well-known problems, resolved by Descartes with onlypartial success. One of his most incisive critics, Elisabeth ofBohemia, wanted to know how in voluntary action the will, which is aproperty of the unextended mind, could have an effect on the body,given that, according to Descartes’s mechanistic physics, a materialthing can be affected only by what is in contact with it. Descartesreplied with a rather mysterious account of how the mind and bodyformed a unique kind of composite. Over the course of the letters oftheir correspondence that focus on this issue, Elisabeth pressesDescartes for an explanation ofhow mind and body interact.Descartes’s responses do not satisfy Elisabeth, and rightly so.For, the mysterious composite that he suggests involves the concept ofaprimitive notion (Shapiro, 65/AT 3:665), a concept that isnot present in any other of his writings. Descartes states that we haveprimitive notions for the body, “extension”, for the mind,“thought”, and for the mind/body composite,“union.” He explains that each of these notions is bestunderstood by using a faculty that is particularly well-suited to graspit. The primitive notion for the mind, he states, is best understood bythe understanding alone; the primitive notion of the body is bestunderstood by the understanding aided by the imagination; and theprimitive notion of the composite is best understood by the senses(Shapiro, 69/AT 3:691). Armed with the distinction in methodology forknowing each of these notions, Descartes diagnoses Elisabeth’sdifficulty in understanding his explanation in the following way: Sheis trying too hard to understand the union of her mind and body by herunderstanding alone. The remedy to this problem, he suggests, is forthe Princess to stop meditating on the problem, and to instead focus on“life and ordinary conversations” in order to conceive theunion (Shapiro, 70/AT 3:692). But, of course, this recommendation doesnot adequately address Elisabeth’s question. For, while focusingon “life” and “ordinary conversations” may wellhelp to conceivethat the mind and body interact, a point thatElisabeth does not call into question, it furnishes nothing towards ananswer to the question ofhow such an interaction occurs. Thediscussion of this topic comes to an end with Elisabeth’ssuggestion that she is better able to understand thehow ofinteraction by thinking that part of the soul is extended (Shapiro,72/AT 4:1). On this model, a necessary condition for motion, contact,is possible.

Descartes’s effort to resolve a second difficulty is more promising,and also exemplifies the rationalistic character of his thought. Theproblem is to show how the mind can know something such as a materialthing that is different in kind from it, given a longstanding principlethat only like can know like. He rejected this essentially Aristotelianprinciple, but still had to give an account of such knowledge. Fromscholastic sources, Descartes was able to construct a theory of ideasaccording to which to know something is to have an idea of it, the ideabeing the very thing known in so far as it is known. He saw the term“idea” as ambiguous: taken materially, it has formalreality, as a mode of the mind; taken in another sense, it hasobjective reality, as the thing represented. But there is no realdistinction between these realities, only a rational distinction. Theyare really the same thing considered differently. A welcomeepistemological upshot of this rationalist gambit is that Descartes hasno skeptical problems generated by ideas standing as atertiumquid between the knower and what is known.

This result is indicated by Descartes’s use of the term, picked upand emphasized by Malebranche, according to which there are nofalse ideas; every idea in this sense is materially true inthat it has an object, and that is the object it appears to have. Thisconception of an idea is the basis for Descartes of what has beencalled the transparency of mind: I cannot be mistaken that I amthinking about what I am thinking about. Malebranche (whose entirephilosophy was colored by his struggles with Descartes’s theoryof ideas), in fact, later erected such incorrigible intentionalityinto the fundamental principle of his epistemology. Meanwhile,Descartes’s view that material or formal reality and objectivereality are only rationally distinct might be taken to mean that mindsare intrinsically intentional. A mind just is the sort of thing whosestates are about something else. Arnauld extended this thesis, whichadumbrates later thinkers such as Brentano, to include all mentalphenomena, even sensations.

Another line of discussion that relates to the problem of dualism andthe nature of ideas is advanced in 1734 by Ghanaian philosopher AntonAmo. An extraordinarily interesting thinker in his own right, Amoadvances a critique of Descartes’s assertion that the mind cansense, that is, that the immaterial mind can passively receive sensoryinformation. In his dissertation,On the Apatheia of the HumanMind,or The Absence of Sensation and the Faculty of Sense inthe Human Mind and Their Presence in our Organic and Living Body,Amo states that the human mind is spirit, and that spirit is thatsubstance that is purely active. Following the narrative of thecommitment to the metaphysical reality of substance as the commonfeature of rationalists through this period, Amo sits firmly in therationalist camp. But it is on the basis of this particular definitionof substance that Amo distinguishes his view fromDescartes’s. According to Descartes, the mind can sense. ForAmo, sensation, which is purely passive, cannot be a feature of thespiritual, purely active substance of mind. There are two threads ofAmo’s critique. First, he is concerned to uphold the soul in thelofty position that it deserves given its status as purely active. Hiscritique of Descartes on this point intersects with the objectionsraised by Elisabeth: the mind, being immaterial, cannot interact withmaterial things. Thus, the mind cannot have sensation of materialobjects (Amo, 75). Second, Amo wishes to emphasize the essentialnature of the body for human beings. On his view, “to live andto have sensation” are inseparable predicates. All living thingsfeel; all feeling things live. But, on his view, “to live”is to be embodied. This allows Amo to call into questionDescartes’s claim, inMeditations II, that he isnothing but a thinking thing. For Amo, it is impossible for the“thinking thing” to live without a body. Amo is thus adualist, like Descartes, but with the important difference of removingsensation from the mind, and locating it in the body. This movesimultaneously preserves the pure activity of the mind and boosts theimportance of the body in the entity that is a human being.

But Amo’s dualism faces the same problem as Descartes’s:if we accept the fact that the body senses and the mind does not, thenAmo must provide an explanation for how the mind and body communicate.In particular, he must provide an explanation for how the body cansense, for instance, pain, and communicate this sensation to thepurely active mind. While Amo might seem no better situated thanDescartes to offer such an explanation, he does endorse an interestingdefinition of “idea” that may provide a starting point forsuch an explanation. Amo states that when we think of the manner inwhich a human being functions, there are four elements that must bekept separate: mind, the operation of the mind, idea, and immediatesensation. Both the mind and its operations are immaterial, he says,and immediate sensation is a property of body. However, on Amo’sview, “idea” is to be understood as “a compositeentity; for there is an idea when the mind makes present to itself asensation pre-existing in the body, and thereby brings the feelingbefore the mind” (Amo, 74). If by “composite”, Amomeans a composite of material and immaterial substance, then thissuggestion bears some resemblance to Elisabeth’s claim, above,that she thinks that there could be a material part of the soul thatcould account for its ability to interact with the body. Of course,explaining just how the mind makes a sensation present to itself andthus brings a feeling before it, will determine the success of anysuch explanation.

3. Malebranche and Cavendish

The battle between the Cartesians and their opponents in the latterhalf of the seventeenth century was one of the great struggles in thehistory of philosophy, but it was one in which the lines were notclearly drawn. For, although those in the Cartesian camp claimed thebanner of Descartes, there were as many differences among them asbetween them and their opponents. Perhaps the most importantdifference among them hinged on whether or not they acceptedDescartes’s doctrine of created truth. Desgabets and his studentRégis were the most important among the few who did accept thedoctrine. Along with their acceptance of the doctrine, however, camenascent tendencies toward empiricism. On the other hand, Malebranche,the most notable among the Cartesians who rejected the doctrine ofcreated truth, developed a philosophical system with a purerrationalistic character than Descartes’s own. Descartes hadadvised his followers to follow not him but their ownreason. Malebranche, like other heterodox Cartesians, justified hisdifferences from Descartes as the result of following thisinjunction. On his view, his rejection of the doctrine of createdtruth followed from his commitment to other, deeper views inDescartes. He thus represented himself as more Cartesian thanDescartes himself.

The philosophy of Malebranche is sometimes portrayed as a synthesis ofDescartes and Augustine, but a more precise way to put this relationis that Malebranche used Augustine to rectify shortcomings heperceived in the philosophy of Descartes. Chief among these wasDescartes’s theory of ideas, which, according to Malebranche,not only fails to reflect human beings’ proper dependence on Godbut also leads inevitably to skepticism. Initially, Malebranchethought that he agreed with Descartes’s theory, but in the longdebate over the nature of ideas he had with Arnauld, who held a closeversion of Descartes’s theory, Malebranche came to see a needfor a different account.

Not implausibly, Arnauld took Descartes’s claim about theambiguity of the term “idea” to mean that“idea”, or “perception”, refers to one and thesame thing, a thing which stands in two different relations. Insofaras it is related to what is known, it is called an idea; insofar as itis related to the mind, it is called a perception. This (act of)perception he took to be related to the mind as a mode of it. It is atthis point that Malebranche detected the threat of skepticism. What weknow, indeed what we know in the most important instances ofknowledge, is universal, necessary, and infinite, as in the case ofcertain mathematical knowledge. But nothing that is the mode of aparticular, contingent and finite mind can be universal, necessary orinfinite. If ideas were modes of the mind, then we would not have suchknowledge; but since we do have such knowledge, ideas must besomething else. Malebranche argued that the only being in which suchideas could exist is God. Following Augustine, he took ideas to be theexemplars in the mind of God after which He creates the world. Thisconstrual had the additional advantage for Malebranche of guardingagainst skepticism because, although idea and object are no longeridentical, they are nonetheless necessarily connected as exemplar andexemplum. Even so, it remained true for Malebranche that, when we lookat a material thing, what we in fact see is not that thing but itsidea. This is the core of his view of “vision of all things inGod”, which he welcomed as an indication of human beings’dependence on the deity. The immediate vehicle whereby we have suchknowledge is a particular, contingent, and finite mode of the mind;but the universal, necessary, and infinite object of that mode canexist only in some other kind of being. How are these ideas known tothe mind if they are not in it, at least not as modes of it? Althoughideas are not innate to the mind, for that would make them modes ofit, they are nonetheless always present to it. In seeking to know,whether we realize it or not, we are consulting Reason, whichMalebranche identifies with the second person of the Trinity,thelogos of Neoplatonic theology. Our effort to know is a“natural prayer” that Reason always answers.

As for individual substances, Malebranche clearly thought that everymaterial thing and every mind is a substance in the sense of ahypokeimenon. But when pressed late in his life to show howthis status for them comported with the rest of his system, how theycould be anything but modes of a single substance, in short how heavoided the drift into Spinozistic monism, he was in fact hardpressed. In theSearch After Truth, Malebranche clearlycommitted himself to the view that everything is either a substance ora mode. In addition, he accepted Descartes’s criterion for asubstance that it be conceivable apart from everything else. However,he maintained that any given portion of extension is conceivable apartfrom the rest of extension and is thus a substance. (Descartes did notthink this, otherwise void space would be possible for him.) Sinceextension is conceptually divisible to infinity, Malebranche iscommitted to an infinite number of extended substances. Apart from thewhole of extension, moreover, every substance contains an infinitenumber of substances, of (each of) which it is a mode. It is also apart of an infinite number of substances, which are modes of it. Theexplanatory value of the concept of substance would seem to have beenlost with such results as these. Malebranche’s view seems to bea degenerate version of Descartes’s texts to the effect,surprising but coherent, that there is but one materialsubstance,res extensa, whose modes are particular materialthings. Here the effect is to reverse the Aristotelian logic ofsubstance. To say of \(x\), a particular thing, that it is extended\(E\), is to say not that a substance \(x\) has a property \(E\), butthat \(x\) is a mode ofres extensa.

These difficulties in accounting for substance on Malebranche’spart seem to derive from his Platonism. As a Platonist, he wasinterested less in substance as thehypokeimenon, whichaccounts for difference, than in its other sense ofousia,which accounts for sameness. Thus, Malebranche’s skid toSpinozism is greased even when he talks about mind, the essence ofwhich is thought—not this or that thought, “butsubstantial thought, thought capable of all sorts of modifications orthoughts”. Since the same substantial thought is had by allpossessed of a mind, Malebranche’s view smacks even of thesingle intellectual soul for all human beings of the LatinAverroists. In this sense too, then, his heterodoxy as a Cartesian ispart and parcel with his deep commitment to rationalism, and inparticular with his rationalistic reduction of phenomenal differenceto real sameness.

The final rationalistic aspect of Malebranche’s thought thatdeserves attention here is his theory of causation. For Malebranche, acause is that between which and whose effect there is a necessaryconnection. On his view, the causal connection that is characterized bythis kind of necessity is that between God’s will and its effects.Thus, for Malebranche, only God has causal efficacy. What we take to bereal causes—for example the motion of a billiard ball thatcollides with another that then begins to move—are in fact onlyoccasional causes, the occasions for the operation of the only realcause.

A cousin of Malebranche’s occasionalism is worth noting here.Margaret Cavendish agrees with Malebranche that bodies do not causechange in one another, but she disagrees with him about whether natureis self-moving. Where Malebranche takes created things to possess nocausal power at all, Cavendish takes them to possess the power ofself-motion. On her view, when bodies interact, there is no transferof motion. Cavendish’s commitment to this view is grounded inher belief that properties cannot be transferred betweenbodies. Because motion is a property, she argues, motion cannot betransferred between bodies. Following this line of reasoning, whenbodies come into contact, they act as occasional causes, that is,causes that merely occasion a change. In an interaction, one body willserve as occasional cause, and the second body will serve as a“principal” cause, which brings about, in itself, the appropriate effect (see Detlefsen 2006 and the entry onCavendish). Both thinkers also hold the view, ubiquitous in the period, that motionis issued into the created world as a result of God’s willing it.Cavendish is careful to note that this issuance is the result not of“an immediate action of God” but rather by an“all-powerful command” (Cavendish, 209). She rejects theformer option on the grounds that such continual, immediate action isunsuitable to “an immovable and immutable essence”(Cavendish, 209). On this point, she and Malebranche are inagreement.

The difference in the way that they conceive of occasional causationis in how they understand the content of the “all-powerfulcommand” that introduces motion into the system. OnMalebranche’s view, a true cause is one where we can perceive anecessary connection between it and its effect. The only candidate forsuch a connection is between the infinite will as cause, and itseffects. Moreover, he seems to also endorse the claim that for a causeto bring out its effect, it must possess the knowledge of how to bringit about. In the case of the relationship between a finite mind andthe body to which it is joined, our ignorance of how the mind“causes” the body to move is enough to deny that there iscausal connection. In short, only God has the required knowledge toeffect these kinds of changes. These arguments undergird the centralMalebranchean commitment: the utter dependence of all created thingson God. As such, it makes sense, on his system, to deny causalefficacy to anything other than God. Such a denial of causal efficacyentrenches the dependence of created things on their creator.

Cavendish tells a different kind of story here. She notes that thosewho show discomfort with the notion that God, through His command,gave the power of self-motion to all created things, are clouded bytheir “ambition” (Cavendish, 209). Ambition leads certainthinkers to imagine that the immaterial substance of their souls isthe only created thing that possesses self-motion. On thisunderstanding of causation, they feel closer to God, who is radicallyself-moving, and superior to material things, which do not possess theability to self-move. However, Cavendish notes, the decree from Godthat introduces motion into the created world is just as easilyimparted to material things as to immaterial things. As such, there isno reason to suppose that He did not give the power of self-motion tomaterial things.

Cavendish’s criticism of those whose ambition clouds the waythey think about self-motion does not apply to Malebranche, however.For, on his view, no created thing, human souls included, possessesthe power to self-move. Given Malebranche’s combinedrationalistic and theological commitments, none of this issurprising. The surprise, or at least irony, comes whenMalebranche’s arguments that natural causes—even andespecially human volitions—cannot be real causes cross thechannel and are deployed by Hume. The radical empiricist account ofcausation that Hume gave in terms of constant conjunction is justMalebranche’s rationalist occasionalism without the roleassigned to God. For Hume, Malebranche’s occasional causes arethe only causes.

4. Spinoza

The centrality of substance for the continental rationalists isfurther borne out by the importance of that concept for Spinoza,especially within hisEthics. Spinoza devoted the entirefirst part of that work to a consideration of substance, or, as healso termed it “Deus sive Natura” (“God, inother words, Nature”). The remaining parts trace theconsequences of his conception of substance for epistemology,psychology, physics, and ethics. While Spinoza’s account ofsubstance is quite rightly regarded as a development and working-outof Descartes’s metaphysics, there are also (as with Descartesand Malebranche) considerable, and important, differences between thetwo. What is important for our present purposes, however, is that (aswith Malebranche) Spinoza’s departures from Descartes are almostalways the manifestation of a form of rationalism purer thanDescartes’s own. Most radically, Spinoza replacedDescartes’s substance pluralism with a monistic account modelledon Cartesian extended substance. Just as, in some places, Descartestreats bodies as mere modes of a single extended substance, so, forSpinoza, all individuals—both bodies and minds—are modesof a single substance.

Spinoza arrived at this position by way of a decidedly uncartesianaccount of attributes. While Descartes held that two substances of thesame type can share the same principal attribute, Spinoza rejectedthis. Any two substances, argued Spinoza, must be distinguished eitherby their attributes (Spinoza dropped the modifier“principal”) or by their modes. But, since modes arethemselves both ontologically and causally dependent on the substancesof which they are affections, they cannot be the individuatingprinciple for them. Thus, it must be the attributes themselves thatindividuate substances (and not justtypes of substances, asDescartes argued). Similarly, while Descartes held that each substanceis characterized by one and only one principal attribute, Spinozainvoked the principle of plenitude to show that substance must haveinfinite attributes. Based on a variation of the ontological argument,he maintained that substance is pure, utterly unlimited being. It musttherefore, he argued, possess infinite attributes, in the dual senseof possessing unlimited attributes and of possessingallattributes. Since substance is characterized by infinite attributes,and since no two substances can share a single attribute, there can beonly one substance. This radical monism was repugnant to many who,like English philosopher Anne Conway, saw that it eliminated any andall distinction between the creator, God, and His creation.

Spinoza’s one substance is at the farthest possible remove fromAristotle’s proper substances. Whereas, for Aristotle,individual things, such as Bucephalus, are paradigmatic substances,Spinoza denies their substantiality. But does this mean that, unlikeAristotelian proper substances, which are not predicable of anythingelse, Spinoza’s finite modes are predicable of substance?Scholars are divided on this point. Curley has argued that Spinozaretains the conception of the substance-mode distinction as adistinction between independent and dependent being, but rejects theview that the substance-mode distinction correlates to the distinctionbetween a subject of predication and its predicate. Bennett, however,argues that Spinoza does indeed regard finite modes as predicable ofsubstance, or, as he puts it, as “adjectival on theworld”. Bennett characterizes Spinoza’s account ofsubstance as a “field metaphysic” in which individualthings are simply clusters of qualities within regions of space. Justas a blush is merely a confluence of properties on a region of a face,so the face—indeed, the person whose face it is—is aconfluence of properties “on a region” of substance.

Whether or not Spinoza rejected the predicability of finite modes, itis clear that he did not regard them as either causally orconceptually independent in the way that is requisite for substance.For Spinoza, substance is “in itself and is conceived throughitself”, whereas a mode is “in something else and isconceived through something else”. The “in itself/insomething else” aspect of these two definitions capturesDescartes’s conception of causal independence, while the“conceived through itself/through something else” aspectrefers to Descartes’s conceivability-apart criterion forontological independence. Descartes, it will be recalled, regardeddivine substance as both causally and ontologically independent, butcreated substances as ontologically, but not causally, independent,since they depend on God’s creative (and conservative) power fortheir existence. It is in this sense that, for Descartes, the term“substance” is used equivocally for God and createdsubstances. Spinoza, however, denied that “substance” isan equivocal term. In so doing, he eliminated two asymmetries inDescartes’s metaphysics—that between divine and createdsubstance, and the asymmetry between extended and thinking substancethat Descartes expresses in the Synopsis totheMeditations. For Spinoza, finite minds are not themselvessubstances, but rather modes of thinking substance. That is, forSpinoza, at the most fundamental level, all minds reduce to thethinking substance of which they are affections.

Spinoza’s account of the eternal verities marks a similarrationalistic advance over Descartes’s metaphysics. For Spinoza,God is just substance simpliciter. He lacks volition and personality;his only characteristics are pure being, infinity, necessity, andactivity. While Spinoza agreed with Descartes that God is the cause ofall things, he regarded him not as a transeunt cause, creating theuniverse “from the outside” through an act of will, but asan immanent cause, from whom the universe unfolds out of his ownnecessity. For Spinoza, all things therefore follow by logical (andnot merely causal) necessity from God’s eternal and infinitenature. In this sense, not only mathematical truths but indeed suchapparently contingent facts as Caesar’s having crossed theRubicon are necessary truths for Spinoza. The difference between themis not the necessity of the truths themselves but rather the routethat we take to arrive at them. While mathematical truths, forinstance, are deducible by reason alone, Spinoza recognized that thefinitude of human understanding prevents, or at least impedes, oursimilarly deducing empirical facts about the world. In contrast withsome empiricists, who regard cause and effect as mere constantconjunction, for Spinoza, the relationship between cause and effecthas the force of a logical entailment; empirical facts are themselvesnecessary truths. The universe is thus, in principle at least,perfectly intelligible to reason.

For Spinoza, as for Descartes, the metaphysical commitment tosubstance underwrote a rationalist epistemology that stronglyprivileges reason and intuition over sensation and imagination. Thedistinctive character of Spinoza’s epistemological rationalismis rooted in his principle that “the order and connection ofideas is the order and connection of things”. For Descartes, themind and the body are, though intimately connected, radicallyheterogeneous. How it is that the mind comes to know things about thephysical world therefore remains, despite his best efforts, a somewhatmurky business. By rejecting the substantiality of both minds andbodies, and by regarding them both as modes of a single substance,Spinoza obviated this difficulty. For Spinoza, the mind and the bodyare the very same thing conceived in two different ways. Persistentclusters of qualities in space are bodies. The ideas—or, inDescartes’s terminology, the objective reality—of thesebodies are minds. Just as a single body has a corresponding objectivereality, so collections of bodies characterized by various relationsalso have a corresponding objective reality with isomorphic parts andrelations. Since there is no gap between minds and bodies, there istherefore no difficulty in principle in perceiving the physicalworld. On Spinoza’s account, we perceive the physical world intwo ways—(1) by perceiving the actions of our own bodies, and(2) by perceiving the effects of other bodies on ours. Thus, whenone’s body runs, the correlative ideas are in one’s mind.Likewise, when someone steps on one’s toe, the physical effectson the toe likewise have their counterparts in the mind’sideas.

Despite the necessary connection the mind has with the body, arguedSpinoza, sensation and imagination are inherently limited. The idea ofsubstance qua substance must be a perfect unity. However, the ideawhich constitutes the human mind is complex—not a unity but aplurality of ideas. That idea is therefore confused, rather than clearand distinct. Clear and distinct understanding, on Spinoza’saccount, must partake of the unity of the idea of substance, and not ofthe fragmentary nature of the idea of the human body and itsaffects. This cognitive unity is achieved in two ways—throughreason (which Spinoza termed “knowledge of the secondkind”) and through intuition (“knowledge of the thirdkind”). When we cognize through sensation and imagination(“knowledge of the first kind”), we try to grasp manyideas at once, and thereby produce confusion. Reason and intuition, bycontrast, provide us with access to just one idea—thesubstantial unity underlying our body and our mind. Reason does thisfrom “the fact that we have common notions and adequate ideas ofthe properties of things”, while intuition proceeds “froman adequate idea of the formal essence of certain attributes ofGod”. To understand the substantial unity that is the necessarycause of our body and our mind is to grasp themsub specieaeternitatis.

This epistemological ideal forms the core of Spinoza’s rationalisticethics—and, hence, on one plausible account, the core of hisEthics. Spinoza’s monism entails that the sort ofindividuals that Aristotle regarded as primary substances aredistinguished not by their own substantial unity, but by theirconatus—their striving to persist. Thus, self-preservation isnot just one possible goal of ethical agents; it is the very thingthat makes those agents individuals. Our essence, and our ethicaltask, is thus to be active, whereas, by contrast, to be passivethreatens our persistence. The mind persists through activity and isthreatened by passivity. It is therefore in our self-interest topursue adequate ideas through knowledge of the second and thirdkinds. The more we join our minds with God through adequate knowledgeof things under the form of eternity, the less we are affected byexternal things and, hence, by our own passions, which are nothing butour passivity in the face of forces external to us. Adequate knowledgeof God gives us equanimity and calm, and literally ensures ourpersistence. Ethical virtue is thus fundamentally epistemological. ForSpinoza, the most rationalist of figures discussed here, the good lifeis the utterly rational life.

5. Leibniz and Conway

As we have seen, rationalist epistemology is grounded in ametaphysical commitment to substance. The concept of substance allowedthe rationalists to reduce all complexity and plurality to anunderlying simplicity and unity, versus the empiricists, who, in theirskepticism about substance, were committed to regarding reality asfundamentally plural and complex. Spinoza’s metaphysics markedthe culmination of this rationalist momentum. In Leibniz, the lastgreat continental rationalist, we see its final movement. Leibniz,like other rationalists before him, regarded quotidian things asphenomena that ultimately reduce to perfectly simplesubstances. However, for Leibniz, there is an infinite number of thesesimple substances, each of them causally and perceptually isolatedfrom all of the others. Leibniz reasoned that this is the best of allpossible worlds because it balances the maximal possible complexitywith the maximal possible order. In thus privileging neither unity norplurality, neither simplicity nor complexity, and in striking thebalance that he did on purely rational principles, Leibniz exemplifieda more complex, more comprehensive and, ultimately, more maturerationalism than that of his predecessors.

For Leibniz, at the most fundamental level, reality is characterizedby simple substances, or “monads”, a term that Leibnizpicked up from Francis Mercury van Helmont and Anne Conway in 1696(Merchant 1979). Since there are composites, Leibniz argued, theremust be simple substances that, together, constitute thesecomposites. Being simple, monads have neither parts, nor extension,nor form, nor divisibility. Leibniz saw them as the “true Atomsof nature”. While Leibniz thus retained a strong commitment tosubstance, he resisted rationalism’s synechistic momentum, whichprivileged the metaphysical and methodological stance of thecontinuity of the universe, by rehabilitating substance’sAristotelian role as an individuator. However, while, for Aristotle,Bucephalus is a proper substance, Leibniz regarded Bucephalus not as asubstance but as himself comprising a collection of simplesubstances. Leibniz agreed with Aristotle’s characterization ofsubstance as the grammatical subject of predication and not itselfpredicable of anything else. However, he complained that this accountdoes not go far enough. For Leibniz, the essence of substance lies notin the fact that it is the subject of predication, but in the factthat every possible predicate may be asserted or denied of it. In thisway, every individual substance has a complete concept, a conceptionso complete (that is, so fully determinate) that every fact about thesubstance, and about its situation in the universe—past, presentor future —follows from it analytically.

Leibniz’s insistence that every individual substance has acomplete concept entailed that, unlike Spinoza, he regarded Cartesianthinking substance and not Cartesian extended substance asparadigmatic of substance. Descartes’s extended substance (likeSpinozistic substance) is, on Leibniz’s account, not a substanceat all since it does not afford a principle of individuation. Leibnizargued that, whereas a real substance has a complete concept, theCartesian notion of extended substance is an abstraction arrived atthrough an incomplete concept. Matter on its own is insufficient toform or to constitute a substance. For Leibniz, a body could never bea candidate for substance since bodies are susceptible to alterationand are infinitely divisible. We can thus never arrive at a body ofwhich it can be said, “Here really is an entity.”Moreover, whereas Cartesian extended substance is totally inert,Leibniz insisted that activity is the hallmark of substance. Anythingthat acts is a substance; every substance constantly anduninterruptedly acts. For Leibniz, this position follows fromGod’s perfection. God’s planning of the universe was soperfect that it only required to be set in motion by him. Truesubstances (that is,entia per se) are active andself-causing. On Leibniz’s account, God would lack all dignitywere he the sole cause in the universe—that is, if occasionalismor interventionism were necessary. God’s perfect planningavoids the necessity for (continual or continuous) extraordinaryconcourse. Thus, God’s perfection entails that all substancesare active; passive extension is only matter, not substance.

The activity, orappetition, that Leibniz regards ascharacterizing the monads is intimately bound up with his Principle ofSufficient Reason. For Leibniz, a monad contains its whole historybecause each monadic state (except for those states—creation isparadigmatic of these—that are the result of divine causation)has its sufficient cause in the preceding state. In turn, the presentstate is the sufficient cause of all succeeding states. Despite thisemphasis on the inherent activity of substance, Leibniz, like Spinoza,rejected the possibility of transeunt causation among substances.Monads are “windowless” and neither admit nor emit causalinfluence. Moreover, being thus windowless, monads can no more receiveperceptions from the world than they can any other external causation.Rather, a monad’s perceptions are built-in at creation. Bypreestablished harmony, these perceptions perfectly align with theuniverse’s infinite monadic states. This entails that whilethere is no genuine transeunt causation at the monadic level, a kindof pseudocausation results from monads’ harmonized perceptionsof each other as their respective appetitions convey them throughsuccessive changes. For Leibniz, causal relations thus reduce tological relations in that every change in a substance follows from itsconcept.

While Leibniz’s view that every substance has a complete conceptreinforces the centrality of reason in his epistemology, in doing so,it seems to undercut human and even divine volition, and thereby toslide toward Spinozism. If every fact about Julius Caesar, and indeed,every other fact about the universe is rationally deducible from theRoman Dictator’s complete concept, then it would seem that onlyone course for the universe is possible. However, this is not a stepthat Leibniz was willing to take. Were there no distinction betweencontingent and necessary truths, argued Leibniz, fatalism would betrue, and human liberty of the will would be impossible. Leibnizsought to avert this result by distinguishing between hypothetical andabsolute necessity. Absolute necessity, he argued, is governed by theprinciple of contradiction. Something is absolutely necessary if itsnegation is logically impossible. Hypothetical necessity, on the otherhand, describes a state of affairs that is necessaryexhypothesi—that is, just in case a particular antecedentholds—but not logically necessary. On Leibniz’s account,the fact that Caesar crossed the Rubicon is only hypotheticallynecessary; it follows necessarily from the existence of the individualsubstance that is Caesar, but its denial is not logicallyimpossible. According to Leibniz, God at creation conceived of aninfinite array of possible worlds. The myriad contingent facts of eachof these worlds are only hypothetically necessary. That is, they wouldonly be necessary if God were to instantiate that world. Since thepresent world is the one that God chose to instantiate, all of thecontingent facts of this world are certain. However, they arenonetheless contingent since their negation implies no absurdity. Thatis, there was no logical impossibility preventing Caesar from decidingnot to cross the Rubicon. In this sense, his will—and, indeed,human will generally—is free. Leibniz’s argument forhypothetical necessity has an obvious antecedent in Descartes’sdoctrine of created truth. However, unlike Descartes, Leibniz limitedthe doctrine’s scope to contingent truths. He nonetheless hopedto avoid Spinozist necessitarianism. Whether or not he succeeded indoing so is a matter of debate in the literature.

Inasmuch as it characterizes the universe as composed of a pluralityof individual existences, none of which has any genuine causalefficacy over any other, Leibniz’s position shows considerableaffinities with Hume’s empiricism. However, while Hume inferredfrom this the importance of experience, Leibniz instead took thisontology to preclude adventitious knowledge. He thus remainedcommitted on metaphysical grounds to the doctrine of innate ideas. Inhis rejection of transeunt causation among substances, Leibnizrejected the notion that we can learn new things about the world inthe sense of gaining new ideas that do not already exist in oursouls. On Leibniz’s account, the temporal coincidence of acertain phenomenon with one’s “learning” of thephenomenon was preestablished at creation in the same way that allmonadic states were. Leibniz admitted that it is idiomaticallyacceptable to speak about acquiring knowledge via the senses. However,he regarded all sensory reports as reducible to, and explicable as,descriptions of logical relations. Leibniz’s theory of knowledgethus relegates the Aristotelian idea of human beings as blank slateswho learn through induction to a merefaçon deparler. By contrast, he strongly endorsed Plato’s doctrineof recollection to the extent that it locates all knowledge in ideasalready residing in the soul. Socrates’s exchange withMeno’s slave boy, argued Leibniz, shows that the soul alreadypossesses the ideas upon which truths about the universe depend, andneeds only to be reminded of them.

On Leibniz’s account, substances have built into themperceptions of the whole universe. Every substance, he argued, is amirror of the whole universe to the extent that everything that hasever happened or existed or will ever happen or exist are included inits complete concept. The perceptions of all substances, hemaintained, thus resemble God’s infinite perception in theirunlimited scope. It is with respect to clarity and distinctness thatthe perceptions of created substance fall short of God’s. ForLeibniz, the best of all possible worlds is that world that balancesthe maximal possible complexity with the maximal possible order. Theexisting world satisfies this through the infinite variety ofperspectives taken by the monads. By the principle of order, eachmonad reflects the very same world as do the other monads. However, bythe principle of complexity, the monads reflect the world from aninfinite number of unique perspectives. This infinite variety inperspectives entails that each monad reflects all of the others withvarying degrees of clarity and distinctness. In this way, the universeis replete with an infinite number of different representations ofGod’s works. Among these, only God’s perceptions areuniversally clear and distinct. While the complexity requirement forthe best of all possible worlds would seem to preclude in principlethe possibility of human beings achieving knowledge of theuniversesub specie aeternitatis, Leibniz made a specialexception for human souls. On Leibniz’s account, all monads havelow-level perceptions, of the kind that we experience when we are in astupor. However, the souls of living things have, over and above this,feelings and memories. Human souls have, besides this, through divineelection, the power of reason. It is reason that allows us tounderstand the universe as a system, through the use of models andidealizations, and thereby to grasp the eternal truths. In this way,argued Leibniz, human minds are not only mirrors of the universe ofcreated things, but indeed mirror God himself.

Leibniz is committed to the view that, given God’s perfection,anything God creates must also be perfect—this is why thecreated world is the best possible world. This means that a large partof his writings are theodicean in spirit. Leibniz shares this spiritwith his close contemporary, Anne Conway. Conway’s system ismotivated by her desire to reject Cartesian dualism, Spinozism, andHobbesian materialism. On her view, any commitment to the existence ofmaterial substance is a commitment to the existence of “deadmass”. Any such view is gravely mistaken. For, she holds thatnature is shot through with the “vital principle ofmotion”, which has life and perception, qualities befitting anycreation of God (Chapter IX, section 2). Conway thus rejectsDescartes’s dualism, while nevertheless noting that because heaccepts the immateriality of God, he is at least better than Hobbes,who holds that God is material. Finally, she registers that herdisagreement with Spinoza has to do with his monism, which effaces anydistinction between God and creatures (Chapter IX, section 3).

To avoid the problem that she identifies with Descartes and Hobbes,Conway asserts a monism: all creatures are composed of one kind ofsubstance—spiritual. To avoid the problem she associates withSpinoza, Conway asserts that while only one (spiritual) substanceexists, the universe is divided into three “species” thatdiffer in their essences: creatures, Christ, and God. This tripartiteseparation is grounded on the basis of the changeability of themember(s) of the species: the essential feature of creatures is thatthey can change for the better and for the worse, the essentialfeature of Christ is that he can only change for the better, andGod’s essence is that He is unchanging (Chapter VI, section4). In postulating these three “species” of the onesubstance, Conway is able to assert God’s separation fromcreation, as well as a metaphysically and morally mediating role forChrist. This mediating role for Christ is of central importance toConway’s theodicy. On her view, accepting this tripartitedivision of species “will contribute greatly to the propagationof the true faith and Christian religion among Jews and Turks andother infidel nations” (Chapter VI, section 5). This is becauseonce we appreciate the reasoning in favor of a mediator betweencreatures and God, and we accept this reasoning, we believe in Christwhether we call the mediator by that name or not. In this way, Conwaycan answer a particularly difficult challenge to any Christianthinker: how can Christianity be the universal religion, in whichsalvation depends on knowing Christ, when so much of the Earth’spopulation is ignorant of Christ? On her system, she can assert thatmany people may know Christ as mediator, without knowing him by nameor even by role in the Christian religion.

While the rise of British empiricism and of Kant’s criticalphilosophy marked the end of continental rationalism as a movement,the elegant visions of Leibniz and Conway are a fitting paean to themovement and, indeed, to the power of human reason.

6. Beyond Continental Rationalism: Other Voices

Since the early twentieth century, “continentalrationalism” has been profitably juxtaposed with “Britishempiricism”. The juxtaposition turns on the notion that therationalist views that were popular on the “continent”were contemporaneous with the empiricist views that dominated thephilosophical conversations in Britain.

While the demarcation between rationalism and empiricism may be usefulas an interpretive and pedagogical tool, it should be borne in mindthat it is a construction in retrospect. The distinction betweenEmpirici andDogmatici is traceable from ancientRoman medicine to Baconian (both Roger and Francis) philosophy ofscience. While Kant and his early commentators imported thedistinction into philosophy, the terminology of“rationalism” and “empiricism”, and theassociation of these terms with, respectively, the Continent andBritain emerged at the end of the nineteenth century (Aaron Wilson,16–20).

In recent years scholars have problematized both the generalrationalist/empiricist distinction and the “continentalrationalism”/“British empiricism” divide. As Nortonhas shown, the “British” in “BritishEmpiricism” can be called into question when we take notice ofthe important role played by the French philosopher Pierre Gassendi inthe propagation of empiricist thinking in the period (Norton 1981).Indeed, British philosophers in the relevant historical period werefar less disconnected from the Continent than they aretoday. Philosophical crossings from Britain were frequent andfruitful. In particular, Locke, Berkeley, and Hume all crossed theChannel. Further, Loeb (1981) argues with some plausibility that therationalist-empiricist divide neglects strong rationalist strands inLocke’s and Berkeley’s thought. Increasingly, scholars ofthe early modern period (but again, recall Goldstone’s critiqueof early modernity as a periodization) are looking outside the boundsof the rationalist/empiricist distinction in order to more accuratelycapture the intersections and divergences present in the constellationof ideas in the period.

Indeed, problematizing the distinction between continental rationalismand British empiricism offers benefits beyond the possibility forgreater interpretative nuance and accuracy. In earlier sections ofthis entry, we troubled the association of rationalism with theContinent by considering British philosophers Margaret Cavendish andAnne Conway alongside Malebranche and Leibniz, and Ghanaianphilosopher Anton Amo alongside Descartes. A focus on seventeenth andeighteenth century rationalists, broadly conceived, as opposed tocontinental rationalists in particular, makes possible theinclusion in the conversation of other figures—notably, womenand non-Europeans—who did not live on the Continent but who marknodes of influence and importance in rationalist thought. Thus, anadditional strong motivation to call the distinction into question isin an effort to include other voices in this period.

Before we consider two final rationalist women philosophers fromBritain, a brief digression is in order on the degree to whichrationalism permitted the philosophical participation of women (and toa lesser extent of racialized others).

It is by now a familiar trope that rationalism excludes women.Genevieve Lloyd famously argues that Descartes’sreconceptualization of reason as an attainment, and as an attainmentachieved by pure mind uncorrupted by sensuality and society,unintentionally (but significantly) excludes women—whosedomestic roles inevitably involved the sensual and the social (Lloyd1984/1993, 40–51). Susan Bordo characterizes Cartesian“objectivism and mechanism” as a “flightfrom the female cosmos and ‘feminine’ orientation towardsthe world” (Bordo 1987, 100, emphasis in the original). Whetheror not rationalism constitutively excludes women, it is clear thatsome individual rationalists do so. See, for instance, HasanaSharp’s argument that Spinoza sees the better but does the worsein his assertion in thePolitical Treatise that women are naturally unequal to men(Sharp 2012).

Against the characterization of rationalism as excluding women,Margaret Atherton draws on Mary Astell and Damaris Lady Masham toargue that in fact rationalism offered a framework in which women(and, one presumes, members of non-European cultures) could dophilosophy. By prescribing a method of reasoning that doesn’t hinge ona particular education or social standing, argues Atherton (afterAstell), rationalism reconceptualizes reason as in principle possiblefor all humans—man and woman, Plow-man and Doctor (Atherton,32). Erica Harth traces the history of sixteenth and seventeenthcentury French “salon women” and offers evidence thatDescartes’s clear, jargon-free French and commitment to beingintelligible by lay people made Cartesianism appealing to the womenwho regularly participated in philosophical salons. Further, Harthreconstructs the thought of the prominent salon women to show thatthey extend Cartesianism in novel ways (Harth 1991). However, shenotes that most of what comes down to us from French Cartesianism ofthe day originated in the male-only academy, and not the salons.

Whatever the remaining legacy of Cartesian women in France, Astellremains an important interpreter and proponent of Descartes’sepistemological method, a method she explicitly endorses as the basisfor supporting the education of, and philosophical inquiry by, women.In her two-part 1694 and 1697A Serious Proposal to the Ladies:Wherein a Method is offer’d for the Improvement of theirMinds, Astell urges that meditation (in Descartes’s senseof that term) avails itself to all who apply themselves to it withdedication. She admits that those (women or labourers, for instance)whose circumstances do not permit them to contemplate truth may atfirst find such contemplation unfruitful. However, she proposesreading, discoursing, and serious meditation as remedies to thissituation. While Astell rejects the view that some people’sembodiment make them more suited for practical than intellectualpursuits, she acknowledges that some reasoners’ animal spiritsmay incline them to volatility of thought; she therefore counselsreasoners to withdraw their minds from their bodies and the materialworld. Alice Sowaal identifies in Astell three central rationalistthemes: “an emphasis of the mind over the body; a theory ofinnate ideas as the origin of knowledge; and a methodology that leadsthe novice from confusion to clarity” (Sowaal). Astell bolstersher Cartesian method with a theological argument that God would notcreate naturally defective rational beings, and hence that all humanbeings are capable of rational thought. If women are at first unableto reason well, it is the result of their circumstances and not theirnature, she argues. Astell thus both draws on Descartes andanticipates Wollstonecraft.

Relaxing the criteria for inclusion in the “rationalist”camp also invites us to appropriately situate the rationalism ofScottish philosopher Mary Shepherd. Shepherd was a sharp critic ofHume’s endorsement of the causal system we might call“Malebranche without God”. Shepherd raised her objectionsto Hume’s theory on the basis of her commitment to thesuperiority of reason for knowledge, and in particular knowledge ofthe truths of causation. Here we see that she shares at least onecharacteristic of those typically ascribed to rationalists, theexaltation of reason over the senses in knowledge acquisition. InAn Essay Upon the Relation of Cause and Effect (1824),Shepherd seeks to dismantle Hume’s causal theory of constantconjunction by arguing that we can indeed have intuitive knowledgethat everything that exists requires a cause. Moreover, on her view,it is reason, not “custom” or “habit”, that isour chief guide in the understanding of our daily lives (27–28).Shepherd’s critique of Hume is important in its own right as avaluable contribution to the philosophical conversation of her age. Itis also, however, representative of the way that the rationalistperspective was being articulated in the first quarter of the 19thcentury. As such, it marks a moment in the history of rationalism.Putting Shepherd into conversation with her fellow rationalists acrosstime only serves to deepen and broaden our understanding of this lineof thinking.

In sum then, while the notion of continental rationalism can be auseful heuristic, especially for teaching and learning, it ought notto be a strict criterion. A less restrictive conception of rationalismnot only supports a more historically accurate, nuanced understandingof philosophical movements in the period; it also renders therationalist canon more diverse. As historians of philosophyincreasingly work to develop more inclusive canons, such areconceptualization is all to the good.

Bibliography

Primary Sources

Amo

• The Apatheia of the Human Mind,or The Absence ofSensation and the Faculty of Sense in the Human Mind and Their Presencein our Organic and Living Body, William Abraham (trans.), inAntonius Gviliemus Amo, Afer of Axim, Translation of hisWorks, Halle: Martin Luther University, Halle-Wittenberg,1968.

Astell

• Astell: Political Writings, P. Springborg (ed.), Cambridge:Cambridge University Press, 1996.
• A Serious Proposal to the Ladies. Parts I and II, P.Springborg (ed.), Ontario: Broadview Literary Texts, 2002.
• The Christian Religion, As Professed by a Daughter of the Churchof England, J. Broad (ed.), Toronto, ON: Centre for Reformationand Renaissance Studies and Iter Publishing, 2013.

Cavendish

• Observations upon Experimental Philosophy, EileenO’Neill (ed.). Cambridge: Cambridge University Press, 2001.

Conway

• Principles of the Most Ancient and Modern Philosophy, AllisonP. Coudert and Taylor Corse (eds.). Cambridge: Cambridge UniversityPress, 1996.

Descartes

• Oeuvres De Descartes, 11 vols., C. Adam and P. Tannery, Eds.,Paris: Librairie Philosophique J. Vrin, 1983.
• The Philosophical Writings of Descartes, 3 vols., J.Cottingham, R. Stoothoff, and D. Murdoch, Trans. Vol. 3 including A.Kenny, Trans., Cambridge: Cambridge University Press, 1984–88.
• The Correspondence Between Princess Elisabeth of Bohemia andRené Descartes, Lisa Shapiro (ed. and trans.), Chicago:University of Chicago Press, 2007.

Malebranche

• Œuvres complètes de Malebranche, 20 vols.,A. Robinet (ed.), Paris: J. Vrin, 1958–84.
• Dialogues on Metaphysics, W. Doney, Trans., New York: AbarisBooks, 1980.
• Dialogue between a Christian Philosopher and a Chinese Philosopheron the Existence and Nature of God, D. A. Iorio (trans.),Washington: Catholic University Press, 1980.
• Treatise on Ethics, C. Walton (trans.), Dordrecht: Kluwer,1993.
• Dialogues on Metaphysics and on Religion, N. Jolley and D.Scott (trans.), Cambridge: Cambridge University Press, 1997.
• The Search after Truth, T. M. Lennon and P. J. Olscamp(trans.), Cambridge: Cambridge University Press, 1997.

Spinoza

• Spinoza Opera, 5 volumes. C. Gebhardt (Ed.), Heidelberg:Carl Winter, 1925–87.
• The Collected Writings of Spinoza, E. Curley (trans. and ed.),Princeton: Princeton University Press, 1985.Complete Works,S. Shirley (trans.), M. Morgan (ed.), Indianapolis: Hackett, 2002.

Leibniz

• Gottfried Wilhelm Leibniz: Sämtliche Schriften undBriefe, German Academy of Science, Darmstadt and Berlin: BerlinAcademy, 1923–.
• Philosophical Essays, R. Ariew and D. Garber (eds. andtrans.), Indianapolis: Hackett, 1989.
• Opuscules et Fragments Inédits deLeibniz, L. Couturat (ed.), Paris: Felix Alcan, 1903.
• Leibnizens Mathematische Schriften, C. I. Gerhardt (ed.),Berlin: Weidman, 1875–90.
• Die Philosophischen Schriften von Gottfried Wilhelm Leibniz,C.I. Gerhardt (ed.), Berlin: Weidman, 1875–90.Theodicy,A. Farrer (ed.) and E. Huggard (trans.), New Haven: Yale UniversityPress, 1952.
• Philosophical Papers and Letters, L. Loemker (ed.), 2nded., Dordrecht: Reidel, 1969.Philosophical Writings, M.Morris and G. Parkinson (eds. and trans.), London: Dent, 1973.
• New Essays on Human Understanding, P. Remnant and J.Bennett (ed. and trans.), Cambridge: Cambridge University Press,1982.
• Leibniz: Selections, P. Wiener (Ed.), New York: CharlesScribner’s Sons, 1951.

Secondary Sources

• Abraham, William, 1964, “The Life and Times of Anton WilhelmAmo”,Transactions of the Historical Society of Ghana,7: 60–81. [A biography of Amo.]
• Adams, Robert Merrihew, 1994,Leibniz: Determinist, Theist,Idealist, Oxford: Oxford University Press. [A careful andpenetrating study that benefits from the author’s extensive ofknowledge of Leibniz’soeuvre.]
• Allison, Henry, 1987,Benedict de Spinoza: An Introduction,New Haven: Yale University Press. [A classic work by an eminentSpinoza scholar. Suitable for beginners, but also useful for thosewell-versed in Spinoza.]
• Atherton, Margaret, 1993, “Cartesian Reason and GenderedReason”,A Mind of One’s Own: Feminist Essays on Reasonand Objectivity, Eds. Louise Antony and Charlotte Witt, Boulder:Westview Press. [Against arguments that Descartes’s conception ofrationality served to exclude women, Atherton here adduces evidencethat some early modern women philosophers regarded Cartesian reason asegalitarian, and were encouraged by it in their work.]
• –––, 1996, “Lady Mary Shepherd’s CaseAgainst George Berkeley”,British Journal for the History ofPhilosophy, 4(2): 347–366. [An analysis of Shepherd’sobjections to Hume, and the manner in which she distinguishes her viewfrom Berkeley’s.]
• –––, 2005, “Reading Lady MaryShepherd”,The Harvard Review of Philosophy,13(2):73–85. [An introduction to both Shepherd’s biographyand her philosophical disputes with Dugald Stewart and JohnFearn.]
• Bennett, Jonathan, 1984,A Study of Spinoza’s Ethics,Indianapolis: Hackett Publishing. [A clear, penetrating study ofSpinoza whose arguments and analogies have entered the scholarly idiom.Essential reading for Spinozists.]
• Bermúdez, José Luis, 1997, “Scepticism and Sciencein Descartes”,Philosophy and PhenomenologicalResearch, 57(4): 743–772. [An argument for separating theimportance of scepticism for motivating Descartes’s project andour interpretation of him as a canonical rationalist.]
• Bolton, Martha Brandt, 201, “Causality and Causal Induction:The Necessitarian Theory of Lady Mary Shepherd”, inCausationand Modern Philosophy, Keith Allen and Tom Stoneham (eds.),242–261. New York/Routledge. [A detailed look at Shepherd’s viewsof cause, causal principles, and mathematical induction. The lattertopic includes some discussion of Shepherd’s dispute with DugaldStewart.]
• Bordo, Susan, 1987,The Flight to Objectivity: Essays onCartesianism and Culture, Albany: State University of New YorkPress. [A classic feminist psychoanalytic study of Descartes’sMeditations.Inter alia, Bordo argues that Descartesreconceives rationality as paradigmatically masculine.]
• Boyle, Deborah, 2009,Descartes on Innate Ideas, London:Continuum. [A comprehensive study of Descartes’s nativism. Boyle arguesthat, for Descartes, we have implicit knowledge of our innate ideas,and that reflection is required to make the knowledge explicit. Thevolume includes a thorough survey and critique of the secondaryliterature on innate ideas in Descartes.]
• Bryson, Cynthia B, 1998, “Mary Astell: Defender of the‘Disembodied Mind’”,Hypatia, 13(4):40–62. [An argument in favor of Astell being the first English,woman feminist. Bryson argues that Astell’s version ofCartesian dualism allows her to reject the subordination of women, andher rejection of the possibility of “thinking matter”allows her to reject the kinds of social contracts between men andwomen that Locke endorsed in his political system.]
• Carriero, John, 1995, “On the Relationship Between Mode andSubstance in Spinoza’s Metaphysics”,Journal of theHistory of Philosophy, 33(2): 245–73. [Carriero traces themedieval Aristotelian influence of Spinoza’s substance/modedistinction, and in so doing challenges Curley’s argument thatSpinozist modal dependence is causal dependence.]
• Cottingham, John, 1984,Rationalism, London: Paladin Books.[A concise, accessible survey of issues in both early modern andcontemporary rationalism.]
• Curley, Edwin, 1988,Behind the Geometric Method,Princeton: Princeton University Press. [A brief, persuasive argumentfor a naturalistic understanding of Spinoza’sEthics by aleader in the field.]
• Della Rocca, Michael, 1996,Representation and the Mind-BodyProblem in Spinoza, Oxford: Oxford University Press. [Theauthoritative work on Spinoza’s theory of ideas.]
• –––, 2005, “Descartes, the Cartesian Circle,and Epistemology without God”,Philosophy andPhenomenological Research, 70(1): 1–33. [An interpretationof Descartes’s system that would allow him to escape the circleobjection.]
• –––, 2008,Spinoza, London and New York:Routledge. [An accessible introduction to Spinoza’s maindoctrines, with a useful sketch of the historical context.]
• Detlefsen, Karen, 2006, “Atomism, Monism, and Causation in theNatural Philosophy of Margaret Cavendish”,Oxford Studies inEarly Modern Philosophy, 3: 199–240. [A discussion of the tensionbetween Cavendish’s monism and her anti-atomism.]
• Donagan, Alan, 1988,Spinoza, Chicago: University ofChicago Press. [A spare, compulsively readable interpretation ofSpinoza’s mature work as a whole, with an emphasis on hisnaturalism.]
• Fantl, Jeremy, 2016, “Mary Shepherd on CausalNecessity”,Metaphysica, 17(1): 87–108. [Anargument that Shepherd’s anti-Humeanism is actually strongerthan has been heretofore appreciated.]
• Fraenkel, Carlos, Dario Perinetti, and Justin Smith, Eds, 2010,The Rationalists: Between Tradition and Innovation, Dordrecht:Springer. [Essays on varied topics by key thinkers in the field, all ofthem devoted to understanding and problematizing the category ofrationalism by considering aspects of key rationalist figures in theirhistorical contexts.]
• Frankfurt, Harry, 1965, “Descartes’ Validation ofReason”,American Philosophical Quarterly, 2:149–56. [A seminal work dealing with the alleged circularity ofDescartes’sMeditations.]
• Garber, Daniel and Michael Ayers, Eds., 1998,The CambridgeHistory of SeventeenthCentury Philosophy, 2 vols.,Cambridge: Cambridge University Press. [This collection provides acomprehensive look at the relevant philosophical period, withinvaluable material about the historical and social context.]
• Garrett, Don, Ed., 1996,The Cambridge Companion toSpinoza, Cambridge and New York: Cambridge University Press.[Essays on all aspects of Spinoza’s thought by top Spinozascholars.]
• Goldstone, Jack, 1998, “The Problem of the ‘EarlyModern’ World”,Journal of the Economic and SocialHistory of the Orient, 41(3): 249–284. [An influentialproblematization of the “early modern” periodization thatin particular identifies the eurocentrism and the myth of progress onwhich the periodization trades. Goldstone also exploresinconsistencies between the manner in which the boundaries of theearly modern era are drawn and usual conventions in historicalperiodization.]
• Guéroult, Martial, 1968,Spinoza I: Dieu, Paris: GeorgOlms. [Guéroult is credited with having dealt Wolfson’ssubjectivist account of Spinoza’s attributes its deathblow.]
• Hagengruber, Ruth, 2015, “Cutting Through the Veil ofIgnorance: Rewriting the History of Philosophy”,TheMonist, 98: 34–42. [An argument in favor of taking thephilosophical writings of women through the history of philosophy ascontributions of general relevance to this history.]
• Harth, Erica, 1991, “Cartesian Women”,Yale FrenchStudies 80: 146–164. [A useful study of the thought of FrenchCartesian women, especially those who were prominent in thephilosophical salons of the seventeenth century.]
• Huenemann, Charles, 2008,Understanding Rationalism,Durham, UK: Acumen. [A clear and helpful introduction to Descartes,Spinoza and Leibniz, written for college juniors.]
• Ishiguro, Hidé, 1972,Leibniz’s Philosophy of Logic andLanguage, Ithaca, New York: Cornell University Press. [A clear,untechnical discussion of Leibniz’s arguments considered in light ofcontemporary angloamerican logic.]
• Jolley, Nicholas (editor), 1995,The Cambridge Companion toLeibniz, Cambridge: Cambridge University Press. [Essays on allaspects of Leibniz’s thought by top Leibniz scholars.]
• Kenny, Anthony, 1998, “Descartes on the Will”, in JohnCottingham (ed.),Descartes, Oxford: Oxford University Press,pages 132–60. First appeared in R.J. Butler (ed.),1973,Cartesian Studies, New York: Barnes andNoble. [Articulation of the “freedom of perversity”interpretation of Descartes’s discussions with Mesland onfreedom.]
• Kenny, Anthony (editor), 1986,Rationalism, Empiricism andIdealism, Oxford: Oxford University Press. [A useful collection,mostly of lectures delivered at the British Academy by leadingscholars of early modern philosophy.]
• Krause, Andrej, 2009, “Amo’sOntology”,Philosophia Africana, 12(2):141–157. [A discussion of Amo’s general ontology and howit informs his commitment to the insensitivity of the humansoul.]
• Lascano, Marcy, 2013, “Anne Conway: Bodies in the SpiritualWorld”,Philosophy Compass, 8(4): 327–336. [Adefense of Conway’s articulation of her monism, with an emphasison the important role for “body” in a system where theonly substance is spirit.]
• Lennon, Thomas M., 1993,The Battle of the Gods and Giants: TheLegacies of Descartes and Gassendi, 1655–1715, Princeton:Princeton University Press. [An account of the contest between theCartesians and their principal opponents as an extension of the battlethat Plato depicts in theSophist between the materialistsand the friends of the forms.]
• Lewis, Geneviève (Rodis), 1950,L’individualité selon Descartes, Paris:J.Vrin. [Discusses all the texts on both sides of the question of theuniqueness of extended substance.]
• Lin, Martin, 2011, “Rationalism and Necessitarianism”,Noûs, 46(3): 418–448. [A discussion ofSpinoza’s and Leibniz’s disagreement over whethermetaphysical rationalism leads to necessitarianism.]
• Lloyd, Genevieve, 1993,The Man of Reason: “Male”and “Female” in Western Philosophy, 2nd Ed., London:Routledge [This influential feminist study traces the construction ofreason as masculine in the history of Western philosophy. Lloyd seesDescartes’s method as a crucial move in the historicalphilosophical centering of masculine thought.]
• Loeb, Louis, 1981,From Descartes to Hume: ContinentalMetaphysics and the Development of Modern Philosophy, Ithaca andLondon: Cornell University Press. [Loeb famously challenges therationalist-empiricist divide, arguing that important aspects ofLocke’s and Berkeley’s thought are rationalist incharacter.]
• Mates, Benson, 1986,The Philosophy of Leibniz: Metaphysics& Language, Oxford: Oxford University Press. [An internalistreading of Leibniz focusing in particular on logical issues and onLeibniz’s nominalism.]
• McCracken, Charles J., 1983,Malebranche and BritishPhilosophy, Oxford: Clarendon Press. [A classic account ofMalebranche’s influence on British philosophy, which also contains awonderful 100 page account of Malebranche’s system.]
• Melamed, Yitzhak, 2013, “Spinoza’s Metaphysics of Thought:Parallelisms and the Multifaceted Structure of Ideas”,Philosophy and Phenomenological Research, 86(3):636–683. [A reinterpretation of Spinozist parallelism that seeksto resolve why human beings can only know two of substance’sinfinite attributes.]
• Merchant, Carolyn, 1979, “The Vitalism of Anne Conway: ItsImpact on Leibniz’s Concept of the Monad”,Journal ofthe History of Philosophy, 17(3): 255–269. [A discussion ofConway’s system, and her influence on Leibniz.]
• Moreau, Joseph, 1947, “Malebranche et le spinozisme”, inJoseph Moreau (ed.),Malebranche: Correspondance avecJ.-J. Dortous de Mairan, Paris: Vrin, pages 1–99. [Moreauprovides an excellent introduction to and analysis of thiscorrespondence in his introduction to this edition of thecorrespondence.]
• Nadler, Steven., Ed., 1993,Causation in Early ModernPhilosophy: Cartesianism, Occasionalism, and PreestablishedHarmony, University Park: Pennsylvania State University Press. [Acollection of essays concerning the three main rationalist theories ofcausation. The essays in this collection consider not only the majorfigures discussed in the above article, but also a number ofintermediate and minor figures.]
• Nelson, Alan, Ed., 2005,A Companion to Rationalism,Oxford, Blackwell. [An ably edited collection of essays devoted to thehistorical antecedents of rationalism, to the movement’s “goldenage” and to rationalist elements in contemporary thought.]
• Norton, David Fate, 1981, “The Myth of BritishEmpiricism”,History of European Ideas, 1(4):331–344. [An argument problematizing the very category of“British Empiricism.”]
• Okruhlik, Kathleen and James R. Brown, Eds., 1985,The NaturalPhilosophy of Leibniz, Dordrecht: D. Reidel. [A challengingcollection devoted to the role of physics and natural philosophy in thedevelopment of Leibniz’s thought.]
• Perry, Ruth, 1986,The Celebrated Mary Astell: An Early EnglishFeminist, Chicago, University of Chicago Press. [An influentialintellectual biography of Astell.]
• Peterman, Alison, 2015, “Spinoza on Extension”,Philosophers’ Imprint, 15(14): 1–23. [An argumentagainst the interpretation that Spinoza takes extension in space to bea fundamental property of physical things.]
• Rozemond, Marleen, 1998,Descartes’s Dualism, Cambridge:Harvard University Press. [A thorough account of the topic indicated,including valuable scholastic background.]
• Russell, Bertrand, 1992,A Critical Exposition of the Philosophyof Leibniz, London: Routledge. [First published in 1900, this workincludes Russell’s classic arguments that the basis of Leibniz’sthought lies in his Aristotelian logic, and that, for Leibniz,relational properties are merely ideal.]
• Schmaltz, Tad, 2002,Radical Cartesianism: The French reception ofDescartes, Cambridge: Cambridge University Press. [A treatment ofthose few—specifically, Desgabets and Régis—whoaccepted Descartes’s doctrine of created truth.]
• Shapiro, Lisa, 2007, “Volume Editor’s Introduction”,in Lisa Shapiro (ed. & trans.),The Correspondence BetweenPrincess Elisabeth of Bohemia and René Descartes, Chicago:University of Chicago Press. [The definitive analysis of thiscorrespondence.]
• –––, 2008, “Princess Elisabeth and Descartes:The Union of Soul and Body and the Practice ofPhilosophy”,British Journal for the History ofPhilosophy, 7(3): 503–520. [An argument in favor of viewingElisabeth as a philosopher in her own right, and not merely acorrespondent of Descartes.]
• Sharp, Hasana, 2012, “Eve’s Perfection: Spinoza on Sexual(In)Equality”,Journal of the History of Philosophy50(4): 559–580. [A study of inconsistencies in Spinoza’saccount of women’s capacities.]
• Smith, Justin, 2015,Nature, Human Nature, & Human Difference:Race in Early Modern Philosophy, Princeton: Princeton UniversityPress. [A useful study of the construction of race in early modernityand its interactions with the philosophical thought of the day.]
• Sowaal, Alice, 2004, “Cartesian Bodies”,CanadianJournal of Philosophy, 34(2): 217–40. [This useful articlesorts Descartes’s inconsistent language about substance in termsof levels.]
• –––, 2007, “Mary Astell’s SeriousProposal: Mind, Method, and Custom”,PhilosophyCompass, 2(2): 227–243. [A discussion of Astell’stheory of mind.]
• –––, 2015, “Mary Astell”, The StanfordEncyclopedia of Philosophy (Winter 2015 Edition), Edward N. Zalta(ed.), URL =<https://plato.stanford.edu/archives/win2015/entries/astell/>.
• Sutherland, Christine Mason, 2005,The Eloquence of MaryAstell, Calgary: University of Calgary Press. [A recent study ofAstell’s importance as a rhetorician.]
• Tollefsen, Deborah, 1999, “Princess Elisabeth and the Problem ofMind-Body Interaction”,Hypatia, 14(3): 59–77. [Adiscussion of Elisabeth’s objections to Descartes’sdualism.]
• Wilson, Aaron, 2016, Peirce’s Empiricism: Its Roots and ItsOriginality, Lanham: Lexington Books. [This study of AmericanPragmatist Charles Sanders Peirce contains a useful chapter on thehistory of the rationalism-empiricism distinction.]
• Wilson, Margaret Dauler, 1982,Descartes, New York:Routledge. [See Chapter Three for a clear and useful discussion ofDescartes’s doctrine of created truths.]
• Wiredu, Kwasi, 2004, “Amo’s Critique of Descartes’Philosophy of Mind”, in Kwasi Wiredu (ed.),A Companion toAfrican Philosophy, Malden, Massachusetts: Blackwell Publishing,Ltd., pages 200–206. [Introduction to Amo’s biography, andmain lines of his critique against Descartes’s theory ofmind.]
• Wolfson, Harry, 1934,The Philosophy of Spinoza, 2 vols.,Cambridge, MA: Harvard University Press. [Wolfson’s is still theclassic argument for the subjectivist account of attributes inSpinoza.]
• Woolhouse, R.S., 1993,Descartes, Spinoza, Leibniz: The Concept ofSubstance in Seventeenth Century Metaphysics, London and NewYork: Routledge. [A deep account of many of the themes covered here,with something of value for readers at all levels.]

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Other Internet Resources

• Catholic Encyclopedia, maintained by Kevin Knight of the New Advent Catholicwebsite. Includes entries on all of the figures discussed in the abovearticle.
• Descartes E Il Seicento, maintained by Giulia Belgioioso (Director, Centro Interdipartmentali DiStudi Su Descartes E Il Seicento), Jean-Robert Armogathe (Centred’études cartésiennes) et al.
• Leibnitiana, maintained by Gregory Brown at the University of Houston.
• Leibniz, maintained by Jan Cover of the Purdue University Department ofPhilosophy.
• Necessarily Eternal, this so-called “Catablog of (All) Things Spinoza” has not been updatedsince 2009. Nonetheless, it houses a very impressive linked list ofactive Spinoza scholars and other useful resources.
• Project Vox, maintained by Duke University, is a valuable online resourcethat aims to give voice to Early Modern women philosophers, whosevoices have been unjustly ignored through most of history. You canfind bibliographies, biographies, teaching tools, and imageshere.
• Studia Spinoziana, maintained by Ron Bombardi, Department of Philosophy,Middle Tennessee State University.

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