It is no secret that G. W. Leibniz is a difficult philosopher tostudy. One central reason for this is that the content of hisphilosophy is extremely challenging. It involves a range of subtledistinctions and paradoxical theses, such as the denial of causalinteraction between substances and the thesis that each substanceexpresses every other substance in the universe. Just as significant,however, is the fact that his philosophical corpus is immense,comprising a bewildering array of letters, notes, essays, and largermanuscripts. These writings span a period of over fifty years. Only asmall number of his essays and one philosophical book, theEssaisde théodicée, were published during his lifetime.None of his published or unpublished works is considered amagnumopus on the order of Spinoza’sEthics orKant’sCritique of Pure Reason. The complexity ofLeibniz’s literary remains forces scholars of his thought toengage difficult questions: how much continuity is there betweenLeibniz’s treatments of particular topics at different times inhis career? On what issues does he attain considered views? Shouldcertain texts be privileged over others in attempting to discernLeibniz’s views? Is Leibniz a deeply systematic philosopher whoaddresses a wide range of problems from the perspective of a unifiedtheory, or does he apply his penetrating mind to a series ofphilosophical problems with little concern for the systematiccoherence of his results?

One important clue for approaching the labyrinth of Leibniz’stexts is a distinction that he draws between esoteric(acroamaticus/acroamatique) and exoteric(exotericus/exoterique) presentations of his philosophy.Roughly speaking an esoteric presentation is one that is fullyrigorous while an exoteric or “popular” presentation isless rigorous but easier to understand, which is more appropriate fora general audience. Leibniz distinguishes between these two modes ofpresentation early in his career and explicitly classifies many of his(later) published works such as theEssais dethéodicée as exoteric. This distinction is clearlyrelevant to the questions raised in the previous paragraph. If it ispossible to distinguish between esoteric and exoteric texts, then themost precise statements of Leibniz’s considered views are likelyto be found in the esoteric texts. Similarly, if Leibniz’streatments of an issue in different works seem to be in tension withone another, one potential explanation of the discrepancy is that onetreatment is esoteric and the other is exoteric.

In order to plausibly use Leibniz’s distinction between theesoteric and the exoteric as an interpretive tool one must have a moredetailed account of how he understands the distinction. This itself isnot an easy matter, however, as Leibniz’s remarks on thedistinction also require interpretation. One challenge forunderstanding his views on this issue is that some of his mostexplicit remarks on it are written quite early in his career. Althoughit is clear that he does not abandon the distinction later in hiscareer one should not uncritically assume that his views on thedistinction do not change over time. A second challenge is thatLeibniz typically does not identify his exoteric texts as exotericwithin those texts. For example, if you were to focus exclusively onwhat Leibniz writes in theSystème nouveau de la nature etde la communication des substances, aussi bien que de l’unionqu’il y a entre l’âme et le corps (Newsystem of the nature and communication of substances, and of the unionof the soul and body)—the first public presentation of hisphilosophy—you would have no idea that it is a popularpresentation of is views. It is only in letters to certain of hiscorrespondents that Leibniz identifies this text as exoteric. And whenhe does identify a text as exoteric he often provides few detailsabout exactly what this is supposed to involve. A third challenge forunderstanding Leibniz’s views is that he does not use the terms“esoteric” and “exoteric” univocally.Sometimes these words are used to distinguish different kinds ofcontent that a philosophy might have; other times they signifydifferent modes of presenting one’s philosophy. It will becrucial to disambiguate these terms as we proceed (see Melzer 2014 foran insightful account of different kinds of esoteric and exotericwriting that have been utilized throughout the history ofphilosophy).

The notion of an exoteric Leibnizian philosophy is often associatedwith Bertrand Russell’s influential interpretation of Leibniz.Russell infamously claimed that the difference between Leibniz’spublic and private writings is so significant that they effectivelycomprise two distinct philosophies: a theologically imbued fantasydesigned to please royalty, and his true philosophy, derived fromaustere logical principles, that he revealed to a select few of hiscorrespondents (Russell 1945). In recent decades Russell’s viewhas been rejected; nearly everyone agrees that there is much morecontinuity between Leibniz’s public and private works thanRussell was willing to admit (see Curley 1972 for a critique ofRussell’s view). And as we will see, the distinction between theesoteric and the exoteric does not involve a simple classification ofhis works depending on whether or not they were published. In order toattain a more accurate understanding of Leibniz’s distinctionbetween the esoteric and the exoteric we must turn to his views on theideal form that metaphysics should take.

• 1. The Ideal Form of Metaphysics
• 2. Esoteric Form and Esoteric Content
• 3. The Primary Function of Exoteric Texts
• 4. Eclecticism and Exoteric Philosophy
• 5. Selective Omission in Leibniz’sSystème Nouveau
• 6. Additional Exoteric Strategies
• 7. Summary
• Bibliography
  • Primary Sources
  • Secondary Sources
• Academic Tools
• Other Internet Resources
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1. The Ideal Form of Metaphysics

Leibniz conceived of metaphysics as an a priori demonstrative science.In its ideal form metaphysics would be presented in a manner analogousto Euclid’sElements, where propositions are rigorouslydemonstrated on the basis of definitions and axioms. The point ofdeparture for this conception of metaphysics is Leibniz’s theoryof truth. Leibniz thought that truth consisted in conceptualcontainment: a proposition is true just in case the concept of thepredicate is contained in the concept of the subject. This impliesthat all metaphysical truths are conceptual truths. Leibniz thoughtthat a concept could be defined by analyzing it into simpler componentconcepts. A rigorous demonstration, for Leibniz, consists in a“chain of definitions” (catena definitionum)where one moves from premises to a conclusion via the substitution ofdefinitionally equivalent terms (A II.i.398; L 198). In order for suchdemonstrations to attain the degree of certainty found in geometrythey would need to be set forth in a purely formal system, whichLeibniz termed his “universal characteristic”(characteristica universalis). The universal characteristicwould allow one to express in a purely formal manner the compositionof any concept on the basis of a set of primitive concepts. Thissystem of representation, in conjunction with a logical calculus forexpressing identity and inclusion relations among concepts, wouldenable one to set forth a strictly demonstrative metaphysics (seeRutherford 1996 for a detailed discussion of Leibniz’sconception of a demonstrative metaphysics).

Leibniz’s conception of an ideal metaphysics was incrediblyambitious. He made impressive progress on the project during hiscareer, though he fell well short of attaining his lofty ideal. Someof Leibniz’s very early texts contain stretches of argument thatare not carefully divided into axioms, definitions, propositions, anddemonstrations, but which could be reconstructed to fit that model.Consider, for example, Leibniz’s unpublished 1672–3Confessio Philosophi (The Confession of a Philosopher).Towards the beginning of this work, after providing definitions of“God”, “justice”, “love”, and“harmony”, he demonstrates that “happiness consistsin the most harmonious state of mind” (A VI.iii.117; CP31). Leibniz then argues (in the voice of The Philosopher):

If all happiness is harmonious (as demonstrated), and all harmony isknown by God (by the definition ofGod), and all experienceof harmony is a delight (by the definition ofdelight), itfollows that all happiness is pleasing to God. Therefore (by thedefinition oflove assumed previously) God loves everyone,and, accordingly (by the definition ofthe just)God isjust. (A VI.iii.117; CP 31)

Leibniz’s demonstration is slightly informal here (as one mightexpect in a dialogue), but it could easily be reconstructed indeductive form. In 1675–6 Leibniz wrote a number of unpublishedpapers and notes on metaphysical topics (most of the papers areincluded in Parkinson’sDe Summa Rerum: MetaphysicalPapers, 1675–1676). These texts include definitions of keymetaphysical concepts and many informal demonstrations of metaphysicalpropositions. In the late 1670s Leibniz completed several short draftsof works that were divided into axioms, definitions, and propositions,although the subject matter of those works was not strictlymetaphysical (seeDe Obligatione Credendi AVI.iv.c.2149–2155 andAnimadversiones in schedam ex BatavisMissam A VI.iv.c.2204–2210). In 1679 Leibniz quicklycomposed a work that was closer to the ideal of a demonstrativescience of metaphysics than anything he had written to date (DeAffectibus AVI.iv.b.1410–1441). It contained a long list ofdefinitions of key terms along with some demonstrations ofmetaphysical principles and theses. Leibniz’s project continuedin the 1680s in a series of extensive definitional studies of keyconcepts (see, e.g.,De Notionibus Omnia Quae CogitamusContinentibus A.VI.iv.a.398–405,Definitiones NotionumMetaphysicarum atque Logicarum A.VI.iv.a.624–630, andTabula Notionum Praeparanda A.VI.iv.a.630–635). By 1690Leibniz had developed a logical calculus for expressing identity andinclusion relations among concepts. Around this time, however, Leibnizbegan to doubt whether it was possible to discover absolutelyprimitive concepts. He also did not succeed in developing his purelyformal system of representation, the universal characteristic. Withoutprimitive concepts or the universal characteristic it was not possiblefor Leibniz to attain his ideal of a fully demonstrative metaphysics.It is plausible to think that Leibniz could nevertheless havecompleted a work that was an approximation of the ideal, written inLatin and using non-primitive concepts. Leibniz insisted throughouthis later years that he could complete a work along these lines. In1710, for example, he explains to correspondent Charles Hugony that inhis (Leibniz’s) recently publishedEssais dethéodicée he set forth one part of his views“in an informal manner” and that he is “thinking of[writing] a Latin work in which I will try to unfold my entiresystem” (G 3:680). And in 1715 Leibniz writes to Biber:

if God will grant me more free time, I will attempt by means ofwell-formed demonstrations to impart to a good portion of my views thecertainty of Euclid’sElements. (LBr 64)

But Leibniz never did unfold his entire system, even in this lessambitious form.

Leibniz’s account of the ideal form of metaphysics provides thebasis for one of the ways that he distinguishes between the esotericand the exoteric. In one of his earliest philosophical works, a veryopinionated preface to an edition of a book by Marius Nizolius,Leibniz distinguishes between esoteric and exoteric modes ofphilosophizing. In this text he claims that the notion ofdemonstration provides the line of demarcation between the esotericand exoteric modes. In the former “all things aredemonstrated” while in the latter less rigorous forms ofargumentation are utilized (e.g., supporting a proposition by means ofan analogical argument). Works written in the exoteric mode, thoughuseful in various respects, are “not most rigorous, not mostexact” (A VI.ii.416). In this and other texts Leibniz equatesthe esoteric mode of philosophizing with the geometrical model ofdemonstration, as briefly described above.

2. Esoteric Form and Esoteric Content

Leibniz advocated the geometrical model of demonstration as the idealform for metaphysics throughout his career. He claimed later in hiscareer that he had all the materials at hand to compose a work thatwas a close approximation of the ideal. Yet such a work he did notcompose. Why did Leibniz not make more progress on this task, whichwould seem to be of such great importance? Leibniz often mentioned hislack of free time as the reason for not completing an esoterictreatise. But this seems to provide an incomplete explanation of thesituation. Though his extra-philosophical duties were numerous andburdensome, he made the time to write quite a lot on metaphysicalsubjects. If he thought that the geometrical model of demonstrationwas indeed the ideal form for metaphysics, one cannot help but wonderwhy he did not find the time to begin composing such a work.

It is likely that there were several additional factors that ledLeibniz to compose exoteric rather than esoteric works. Consider thefollowing remarks on the distinction between exoteric and esotericmodes of exposition in his 1704Nouveaux Essais surl’entendement humain (an unpublished critical examinationof Locke’sEssay Concerning Human Understanding writtenin dialogue form). The remarks occur in the context of a discussion ofthe precision (or lack thereof) in natural language:

The ancients distinguished the ‘exoteric’[exoterique] or popular mode of exposition [maniered’ecrire] from the ‘esoteric’[acroamatique] one which is suitable for those who areseriously concerned to discover the truth; and that distinction isrelevant here. If anyone wants to write like a mathematician inmetaphysics or moral philosophy there is nothing to prevent him fromrigorously doing so; some have announced that they would do this, andhave promised us mathematical demonstrations outside mathematics, butit is extremely seldom that anyone has succeeded. I believe thatpeople are repelled by the amount of trouble they would have to takefor a tiny number of readers: like the question in Persius, ‘Whowill read this?’, with its answer ‘Maybe a couple ofpeople, maybe no one’. Yet I think that if anyone did go aboutit in the right way, he would have no reason to regret his labour. Ihave been tempted to try it myself. (NE: 260–261)

In this intriguing text Leibniz (through the voice of Theophilus)notes that few people have tried to write in the esoteric mode, andeven fewer (if any) have succeeded in the endeavor. He also suggestsseveral reasons that authors avoid esoteric expositions. Esoterictexts are both difficult to compose and unlikely to attract readers,presumably because of their intimidating formal apparatus. And what isthe point of writing a text that no one is going to read? This pointis also emphasized by Leibniz in a 1705 letter to Burnett:

I never write anything in philosophy that I do not treat bydefinitions and axioms, though I do not always give it thatmathematical air, which puts people off, for one must speak in afamiliar manner to be read by ordinary people. (G 3:302)

Despite these significant drawbacks to writing in the esoteric mode,Leibniz insists that if someone pursued this strategy “in theright way” it would be a worthwhile project. In theNewEssays Leibniz does not explain what doing this “in theright way” would involve. He does, however, provide someimportant additional remarks on esoteric philosophy earlier in thetext. In the Preface he points out some key differences between hisphilosophy and the philosophy of Locke:

…although the author of theEssay says hundreds offine things which I applaud, our systems are very different. His iscloser to Aristotle and mine to Plato, although each of us partscompany at many points from the teachings of both of these ancientwriters. He is more popular [populaire] whereas I amsometimes forced to be a little more esoteric [acroamatique]and abstract—which is no advantage for me, particularly whenwriting in a living language. (Preface to theNew Essays, NE:48)

In these remarks Leibniz is using the term “esoteric” in asubtly different way than he is in the earlier quote from theNewEssays. Whereas in the first text “esoteric”designated amode of presenting one’s philosophy, inthis text it concerns thecontent of one’s philosophy.Here he is drawing attention to the fact that his philosophy is less“popular” than Locke’s. Locke’s philosophy ispopular in the sense that much of his philosophy accords with thedeliverances of the senses and so-called “common sense”.Leibniz’s philosophy, in contrast, is often very abstract andfar removed from ordinary opinions. Leibniz elaborates on this pointin a 1702 letter to Sophie Charlotte where he distinguishes betweenthings that can be known through the senses (the“sensible”) and things that are the “object of theunderstanding alone” (the “intelligible”). Leibnizclaims that the existence of “intelligible things”,particularly the “mind or or soul”, is more certain thanthe existence of things that can be sensed. However, many people failto recognize this because “they take sensible things for theonly true things” (G 6:502–3; AG 188–9). Thisoverreliance on the senses makes it difficult for people to understandLeibniz’s metaphysics, which involves a number of things thatsimply cannot be known through the senses. This puts Leibniz at asignificant disadvantage when it comes to trying to communicate hisphilosophy to the general public. Readers are far more likely to findfavor with Locke’s philosophy given that it coheres much betterwith their current beliefs (see Nelson 2005 for more on this generaltheme).

In some of his letters Leibniz makes the point about how difficult itis for most people to understand his philosophy in even strongerterms. Consider, for example, what he writes to Pierre Bayle in1702:

…I should not be in too much of a hurry to publish what I havewritten, the point of which was only to provide some clarification foryou, sir, and for some other people, so as to receive the same inreturn. For I write not so much to make an impression as toinvestigate the truth, which it is often useless, and even harmful, topublish—on account of the uninitiated [des profanes],who are incapable of appreciating it, and quite capable of taking itthe wrong way. (G 3:66–7; WF 127)

These are striking words. Read in isolation from his other remarks onthe exoteric/esoteric distinction, one might take this text to suggestthat Leibniz had two distinct philosophies—a false philosophysuitable for presentation to the public, and his true philosophy,which he only revealed to a few trusted correspondents. ButLeibniz’s claim is not as radical as it might initially seem.While it is true that the esoteric character of the content of hismetaphysics made it susceptible to being seriously misunderstood, hissolution was not to permanently hide his views from everyone who waslikely to misunderstand them. His point, as additional texts will makeclear, is that he thinks it is often useless and harmful tostraightforwardly present the content of his metaphysics tothe public (and even to trusted correspondents). For example, in a1710 letter to Charles Hugony, he claims that some of his views

cannot be presented in a straightforward manner [ne peut donnercruement], since people are likely to misunderstand them …in relation to the senses. (G 3:680)

This suggests that although Leibniz thinks it is unwise to presentsome of his views straightforwardly, there is a way topresent them that is not straightforward. We need to nowconsider what this involves.

3. The Primary Function of Exoteric Texts

Leibniz faced what might seem like an intractable problem. He thoughtthat the ideal form for metaphysics was the esoteric mode ofpresentation. However, he knew that few people were inclined to readtexts presented in the esoteric mode due to their daunting formalstructure. Even worse, Leibniz thought that the content of hisphilosophy was such that most people were likely to misunderstand itin fundamental ways (see Whipple 2015a for a discussion of thisproblem). How then would it be possible for him to communicate hisviews to people? His letter to Hugony, cited earlier, suggested thatit would involve a non-straightforward presentation of his views. Inthat text he did not elaborate on what non-straightforwardpresentation involved, but he did provide more concrete suggestions insome unpublished remarks appended to metaphysical notes written in1676. The quotation is divided into several parts for ease ofreference:

[a] Metaphysics should be written with accurate definitions anddemonstrations, [b] but nothing should be demonstrated in it thatconflicts too much with received opinions. For thus this metaphysicswill be able to be received. [c] If it is once approved, thenafterwards, if any examine it more profoundly, they will draw thenecessary consequences themselves. [d] Besides this, one can, as aseparate undertaking, show these people later the way of reasoningabout these things. [e] In this metaphysics, it will be useful forthere to be added here and there the authoritative utterances of greatmen, who have reasoned in a similar way; especially when theseutterances contain something that seems to have some possiblerelevance to the illustration of a view. (A VI.iii.573)

[a] is best read as a terse reference to the esoteric mode ofpresentation. Although this is the way that metaphysics should ideallybe written, he thinks that it would be a mistake to publish anythingthat “conflicts too much with received opinions”. As wehave already seen, this is because many people will regard it asabsurd, summarily reject it, or misunderstand it entirely (possiblyall three at the same time!). Leibniz suggests a strategy of selectiveomission, not to permanently hide the controversial features of hisphilosophy, but as part of a longer-term strategy of preparing hisreaders to understand his most esoteric doctrines. In some cases hethinks that sympathetic readers who study his texts “moreprofoundly” will be able to infer the esoteric conclusionsthemselves. In [d] he suggests a complementary strategy ofsupplementation. In subsequent works he can explicitly draw theconclusions that may have only been implicit in the initial text.Taken collectively Leibniz’s remarks in this passage suggestthat the primary function of exoteric texts is pedagogical: they aredesigned to serve as intellectual stepping stones that enable hisreaders to gradually move from received opinions to esotericdoctrine.

A number of Leibniz’s remarks in later texts confirm that heconceives of exoteric texts as important preparatory works. Consider,for example, what he writes to Fontenelle in 1704:

The true metaphysics, or philosophy, if you will, does not appear tome any less important than geometry, especially if there is also a wayof introducing into it demonstrations, which until now have beenentirely excluded from it, along with the calculus that will benecessary in order to give them all the entry they need. However, itis necessary to prepare readers with exoteric writings. The journalshave served me well until now. (FC 1:234)

Here Leibniz explicitly claims that his choice to present variousfeatures of his philosophy in journal articles should be understood aspart of a broad exoteric strategy to prepare his readers to understandthe “true metaphysics”. This helps shed light on some ofLeibniz’s better-known remarks about the composition of hisjournal articles. Consider what Leibniz writes to correspondentNicolas Remond in 1714:

In the Leipzig journal [Acta Eruditorum] I adapt myself tothe language of the schools, in the others I adapt myself more to thestyle of Cartesians, and in this latest piece I try to express myselfin a way that could be understood by those who are not yet veryaccustomed to the style of one or the other. (G 3:624)

Leibniz’s strategy of adapting himself to the language of theschools in some articles and to the language of the Cartesians inothers is one of his core exoteric strategies. He thinks that usinglanguage that is familiar with his readers is a good way to make hisviews seem not too far removed from received opinions. This is notmerely a feature of his published writings. Leibniz tailors hiswritings in a similar way in his private correspondences. For example,in his correspondence with Jesuit theologian Bartholomew Des Bosses hefrequently employs scholastic terminology, and in his correspondencewith (largely) Cartesian physicist Burcher De Volder he sometimespresents his views with a Cartesian slant. To use a more concreteexample, early in the correspondence with De Volder, Leibniz appealsto the doctrine of continued divine creation, which he (Leibniz)regards as a central Cartesian tenet. Although he initially presentsthe doctrine in a way that makes it seem like this is a point ofcommon doctrine between him and the Cartesians, it emerges later inthe correspondence that Leibniz only affirms the doctrine in aqualified sense (for a detailed discussion of this issue see Whipple2011). The general strategy here is to use language that is familiarto the reader or correspondent and to emphasize initial points ofagreement. Fine-grained differences and esoteric implications aretypically avoided at the initial stages of engagement.

One important general point that emerges from Leibniz’s remarksin the letter to Remond is that there was more than one set of“received opinions” that he needed to take into account.The received opinions of a Cartesian and the opinions of someone whowas committed to a version of Aristotelian Scholasticism would bedifferent in fundamental respects. In the letter cited above Leibnizspeaks of another of his works, thePrincipes de la Nature et dela Grace, fondés en raison (Principles of Nature andGrace, Based on Reason), which targets yet anotheraudience—those who are not accustomed to the style of theCartesians or the scholastics. When it comes to exoteric philosophy,one size does not fit all. Different strategies are required forpeople with different backgrounds and views.

4. Eclecticism and Exoteric Philosophy

Leibniz is sometimes described as being an eclectic philosopher. Thereare different ways of understanding eclecticism, but the basic idea isthat an eclectic philosopher is one who incorporates ideas from a widerange of sources. In certain places Leibniz characterizes himself asproceeding along these lines. He famously writes to Remond, forexample, that:

I have tried to uncover and unite the truth buried and scattered underthe opinions of all the philosophical sects, and I believe I haveadded something of my own that takes a few steps forward…mostsects are right in a good part of what they affirm, but not so much inwhat they deny. (10 Jan 1714, G 3:606–7; L 654)

It is undeniable that Leibniz read from an extraordinary range ofsources and that his thought was influenced by a number of thesetexts. Although the precise nature of these influences is a matter ofscholarly controversy that cannot be engaged in this article, it isimportant to note that Leibniz’s exoteric strategies bearsignificantly on this general topic. Recall the final sentence in thelong quotation from Leibniz’s 1676 notes on exoteric philosophy:

In this metaphysics, it will be useful for there to be added here andthere the authoritative utterances of great men, who have reasoned ina similar way; especially when these utterances contain something thatseems to have some possible relevance to the illustration of a view.(A VI.iii.573)

Appealing to similarities between his views and those of hispredecessors is one of Leibniz’s strategies for presenting hisphilosophy in a way that makes it seem to be not too far from receivedopinions. We need to remain open to the possibility thatLeibniz’s proclamations of continuity between his thought andthe thought of his philosophical forebears often mask subtle or not sosubtle differences between their respective views. Nuanced differencesand radical implications may be left implicit or omitted entirely inhis more exoteric works. One might put the point as follows. Leibnizis not merely finding ideas in other philosophers and incorporatingthem whole cloth into his philosophical system. In some cases, atleast, Leibniz develops distinctive philosophical views and then seeksout similar ideas in his predecessors as a strategy for presenting hisviews to the public (see Schepers 2008 and Mercer 2001: 23–59for more on this topic).

5. Selective Omission in Leibniz’sSystème Nouveau

Leibniz first presented his philosophy to the public in an essaytitled “Système nouveau de la nature et de lacommunication des substances, aussi bien que de l’unionqu’il y a entre l’âme et le corps”(New system of the nature and communication of substances, and ofthe union of the soul and body). This essay was published in 1695in theJournal des savants. If one were to read this essay inisolation from Leibniz’s other writings (as would have been thecase with most of his readers) one would likely have no idea that itis an exoteric text. He prefaces the essay in the following way:

Finally, since some important persons have desired to see my opinionsfurther clarified, I have risked publishing these meditations, eventhough they are not at all popular [populaires], nor can theybe appreciated by all sorts of minds. I have decided upon this mainlyto profit from the judgments of persons enlightened in these matters,since it would be too troublesome to seek out and call individuallyupon all those who would be disposed to give meinstruction—which I shall always be glad to receive, providedthat it contains the love of truth, rather than a passion forpreconceived opinions. (G 4:477; AG 138)

Note that Leibniz claims that his meditations are “not at allpopular” and that many people will not be able to appreciatethem. These remarks, in conjunction with the comment on preconceivedopinions, are designed to encourage the reader to seriously considerthe views that he will be presenting despite the fact that they willbe difficult to understand and will likely diverge—perhapssignificantly—from the reader’s current beliefs. WhatLeibniz leaves unsaid, however, is that theSystèmenouveau is written according to the exoteric mode ofpresentation. First, the essay is clearly not written in accordancewith the formal apparatus of definitions and demonstrations that isrequired in a strictly esoteric presentation. Second, and perhaps moresignificantly, Leibniz purposefully omits some of the mostcontroversial features of his philosophical system in this essay.

In order to more fully appreciate the exoteric features of theSystème nouveau it will be helpful to consider thistext in relation to Leibniz’s earlierDiscours demétaphysique (Discourse on Metaphysics). Leibnizwrote theDiscours in 1686. Although it was not publishedduring his lifetime, this text has become one of Leibniz’s mostfamous works. It is best known for presenting the complete concepttheory of substance. This theory states, roughly, that each substancehas an infinitely complex complete concept that specifies everythingthat will ever happen to that substance. It is contained in thecomplete concept of Judas, for example, that he betrays Jesus (alongwith everything else that can be truly predicated of Judas). Leibnizwas well aware that his readers might think that the complete concepttheory implies that all of a person’s actions are necessary, andthus that no person is free. In the main text of theDiscoursand in its section headings Leibniz attempts to show that Judas’betrayal of Jesus, for example, is both contingent and a free actiondespite being foreseen in Judas’ complete concept for alleternity. Part of Leibniz’s strategy for showing this is hisclaim that Judas’ reasons for betraying Jesus “inclinewithout necessitating”. Leibniz’s discussion of thesethorny philosophical issues is exoteric, at least to a certain degree.Like theSystème nouveau it was not written in strictaccordance with the esoteric mode of presentation. And arguably,Leibniz’s use of language such as “inclination withoutnecessitation” is carefully chosen with the aim of making hisposition seem closer to received views.

The section headings of theDiscours were sent to AntoineArnauld, a well-regarded theologian and philosopher of the day, to seehow the text would be received. Leibniz could not have been encouragedby Arnauld’s response:

I find in these thoughts so many things which alarm me and whichalmost all men, if I am not mistaken, will find so shocking, that I donot see of what use a writing can be, which apparently all the worldwill reject. (G 2:15)

Arnauld singled out as an example the complete concept theory ofsubstance, which he took to imply a “more than fatalnecessity” that would undermine the very possibility of humanfreedom. Leibniz’s attempts to forestall this implication in thesections headings of theDiscours had not worked as planned,at least for Arnauld. Leibniz attempted to assuage Arnauld’sconcerns in subsequent letters with moderate success.

It is no surprise that Leibniz chose not to publish theDiscours. It is also no surprise that the complete concepttheory of substance does not make an appearance in theSystème nouveau. This does not imply that Leibnizabandoned the complete concept theory; it might just be that he cameto realize that it was not the most effective way of introducingreaders to his philosophical system. Leibniz utilizes the exotericstrategy of selective omission, choosing to avoid a detaileddiscussion of necessity and contingency. Instead he introduces histheory of substance by appealing to the less controversialcharacteristics of unity and activity, and by trying to show how histheory could resolve the notorious problem of mind-body interaction.Letters to some of Leibniz’s correspondents confirm that he was“testing the waters” in theSystèmenouveau, and that he would reveal more of his system to thepublic if it was well received. He writes to Simon Foucher, forexample:

If the public receives these meditations well, I will be encouraged tooffer in addition some rather remarkable ideas I have for alleviatingthe difficulties concerning fate and contingency, and to clarify anessential distinction that can be drawn between material forms andintelligences or spirits. (1695, G 1:423)

Leibniz’s aim was not to permanently hide his views oncontingency, fate, and freedom. By selectively omitting some of thesemore controversial features of his system he increased the likelihoodthat his readers would grasp the features of his system that werepresented in theSystème nouveau. Once they endorsedthese parts of the system they would be more receptive toLeibniz’s views on more controversial topics. Such wasLeibniz’s hope, in any case.

Leibniz returned to the topics of fate, necessity, and contingency inthe one philosophical book that he published during his lifetime, theEssais de théodicée of 1710. It has beensuggested in the secondary literature that Leibniz’s treatmentof necessity and contingency in this text is exoteric to a significantdegree (Adams 1994:52). For example, Leibniz frequently uses termssuch as “inclination without necessitating”, “moralnecessity”, and “hypothetical necessity” withoutproviding strict definitions of them. Some of Leibniz’spredecessors understood these terms in ways that implied anon-deterministic view of human action. According to mostinterpretations of Leibniz’s considered views on these issues(based on a number of texts other than theEssais dethéodicée), he was committed to a strictdeterminism (but not necessitarianism) about human actions. However,by omitting definitions of terms like “moral necessity” intheEssais de théodicée Leibniz might haveallowed readers that were committed to non-deterministic accounts of“moral necessity” to assume that he was using this conceptin a way that was less deterministic than his considered view allowed.This is in keeping with Leibniz’s stated strategy of notpresenting anything to the public that is too far removed fromreceived opinions. One way of not presenting something to the publicthat is far removed from received opinions is to selectively omit it(his strategy in theSystème nouveau). Anotherstrategy is to present a view that is far removed from receivedopinions in a way that makes it seem less removed than it actually is.If Leibniz is utilizing this latter strategy in the discussions ofnecessity and contingency in theEssais dethéodicée, it does not imply that he is trying topermanently mislead his readers. As we have seen, he has severalgeneral strategies for helping his reader progress to a more rigorousunderstanding of his views. One of the strategies is to provide subtlehints such that a “more profound” examination of the textwould yield a deeper understanding. By omitting clear definitions ofterms such as “moral necessity”, however, it is not clearwhether there is enough material in theEssais dethéodicée for even a discerning reader to graspLeibniz’s views on necessity and contingency. But Leibniz didnot claim that such inferences could always be made on the basis of anexoteric text alone. In a number of cases his exoteric treatments needto be supplemented by a more rigorous work. And we must keep in mindthat Leibniz clearly did conceive of theEssais dethéodicée in precisely this way (see Antognazza2009: 481–2). He writes to Charles Hugony shortly after itspublication:

My essays on the goodness of God, the freedom of man, and the originof evil have been printed in Holland, but I did not want to put myname on them. They are woven together from what I said and wrote atvarious times to the Queen of Prussia, who enjoyed reading M. Bayleand in whose company the difficulties that he raises on these matterswere often discussed. I try to explain one part of my views in arather informal manner [un peu familierement]. As you know,some of my views cannot be presented in a straightforward manner[ne peut donner cruement], since people are liable tomisunderstand them, not in relation to religion, which is stronglysupported, but in relation to the senses. I am therefore thinking of[writing] a Latin work in which I will try to unfold my entire system.(6 November 1710, G 3:680)

Leibniz’s remarks in this passage cohere well with the otherremarks on exoteric philosophy that we have considered thus far. As inthe case of theSystème nouveau and Leibniz’sother journal articles, he conceives of theEssais dethéodicée as a preparatory work that will helpprepare his readers for a more systematic and rigorous presentation ofhis views.

6. Additional Exoteric Strategies

We have seen that the primary function of exoteric texts is to serveas intellectual stepping-stones that bridge the gulf between receivedopinions and esoteric truth. Leibniz utilizes a wide range ofstrategies in his exoteric works, some of which we have alreadydiscussed. Several additional strategies deserve mention as well. Letus begin by returning to Leibniz’s remarks on the distinctionbetween esoteric and exoteric modes of presentation in the 1670Preface to Nizolius:

There is…a vast difference between modes of philosophizing[philosophandi modus], for one is, if I may so speak,esoteric [acroamaticus], another is exoteric[exotericus]. The esoteric mode is that in which all thingsare demonstrated; the exoteric is that in which some things are saidwithout demonstration, but they are still given confirmation by meansof certain similarities and by dialectical arguments, or even byarguments based on definition, but not proposed except dialectically,[and] they are illustrated by examples and likenesses. Such a kind ofspeaking is indeed dogmatic or philosophical; however, it is notesoteric, that is, not most rigorous, not most exact. (AVI.ii.416)

One point that we take Leibniz to be making here is that in exotericcontexts propositions can be treated as hypotheses rather thanproviding rigorous demonstrations of them. He seems to think that incertain cases his readers will be less hostile to a novel thesis if itis presented as a hypothesis than if it is presented as a thesis thatcan be demonstrated from metaphysical principles. Althoughpropositions that are presented hypothetically are not demonstratedthey can be motivated and illustrated by examples, analogies,metaphors, and stories (as he says later on). He does not, however,claim that an esoteric work cannot contain analogies, metaphors, andthe like. It can include these things, which “give a pleasingrespite to a weary soul”, so long as they are carefullydistinguished from the rigorous demonstrations that form the core ofthe work. Leibniz notes that this difference is also observed inmathematics where demonstrations, which are rigorous and exact, arecarefully distinguished from scholia in which reasoning can be treatedin a more familiar manner.

It is striking to look at a text like theMonadologie throughthe lens of Leibniz’s remarks about the distinction betweenesoteric and exoteric modes of presentation in the Preface to Nizolius(and the other texts that we have considered thus far). The text isreplete with analogies, metaphors, and other forms of argumentationthat fall well short of rigorous demonstrations. On the assumptionthat Leibniz remains committed to his early account of the distinctionbetween the esoteric and the exoteric, it follows that even theMonadologie, which has traditionally been taken to be one ofthe definitive statements of Leibniz’s mature metaphysics,contains numerous exoteric features. As in the case of theSystème nouveau, Leibniz does not explicitly flag theexoteric features of this work as exoteric. It is thus easy to mistakeexoteric illustration for esoteric demonstration.

Before considering a few particular examples of exoteric strategies intheMonadologie (and other texts), it is worth reiteratingLeibniz’s explanation of why his philosophy was easy tomisunderstand. In the letter to Hugony quoted earlier Leibniz saidthat he needed to present his philosophy in an informal manner becauseit was likely to be misunderstoodin relation to the senses.The tendency people have to rely on a sensory-based theory ofknowledge is one of the primary stumbling blocks that prevent themfrom understanding his philosophical system. Many of Leibniz’score concepts and principles can only be adequately grasped throughthe intellect, not through the senses or the imagination (see, forexample, Leibniz’s remarks on force inDe Ipsa Natura(G 4:508; AG 159)). One of Leibniz’s main exoteric strategiesfor dealing with this situation is to utilizesensibleanalogies,imaginative metaphors, anecdotes, and stories tointroduce and motivate his abstract concepts, principles, and theses.Such metaphors and analogies enable his readers to attain anintroductory understanding of the thesis or principle in question. Letus consider a few examples.

In explaining the thesis that there is no inter-substantial causationbetween finite substances in theMonadologie, Leibnizfamously says: “monads have no windows through which somethingcan enter or leave” (G 6:607; AG 214). This metaphor of being“windowless” helps the reader attain some understanding ofLeibniz’s thesis, but it will be an imperfect understanding tothe extent that it involves conceiving of monads as beingextended.

Leibniz frequently uses imagistic metaphors to describe God’ssustenance of finite substances. Late in theMonadologie, forexample, he writes:

all created or derivative monads are generated, so to speak, bycontinual fulgurations of the divinity from moment to moment. (G6:614; AG 219)

And in theEssais de théodicée Leibniz uses theanalogy of a heavy-laden boat travelling down a river to explain howGod and finite substances can be said to co-operate in the productionof particular effects in the ordinary course of nature (T 30–1).Both the metaphor and the analogy provide useful but imperfect devicesfor conceiving of things that cannot be sensed or imagined, strictlyspeaking. In reading Leibniz’s texts it is important torecognize that these are only metaphors and analogies—they arenot meant to provide metaphysically rigorous descriptions of divineaction (see Whipple 2015b).

Leibniz is committed to the principle of the identity ofindiscernibles. This principle states, roughly, that it is impossiblefor there to be two numerically distinct substances that arequalitatively identical. In discussing this principle Leibnizsometimes supports it by appealing to an anecdote and other empiricalconsiderations. In the anecdote he recalls discussing the principlewith an “ingenious gentleman” who thought he could findtwo perfectly identical leaves. Princess Sophia, who was observing theconversation, “defied him to do it; he ran all over the garden along time to look for some but it was to no purpose”(4^th letter to Clarke, G 7:372; AG 327–8). Leibnizalso defends the principle by appealing to the empirical results ofthe microscopists: objects that can seem qualitatively identical tothe naked eye (two drops of water, or two drops of milk) are shown tobe different when viewed under the microscope. Neither the anecdotenor the appeal to microscopes is intended to be anything like arigorous proof of the principle of the identity of indiscernibles. Arigorous proof would show how the principle is derivedapriori from other principles such as the principle of sufficientreason.

Few people are likely to interpret Leibniz’s anecdote concerningthe principle of the identity of indiscernibles as a rigorousargument. Other cases are more easily misunderstood, however. Considersection 17 of theMonadologie:

…perception, and what depends on it isinexplicable interms of mechanical reasons, that is, through shapes and motions.If we imagine that there is a machine whose structure makes it think,sense, and have perceptions, we could conceive it enlarged, keepingthe same proportions, so that we could enter into it, as one entersinto a mill. Assuming that, when inspecting its interior, we will onlyfind parts that push and pull one another, and we will never findanything to explain a perception. And so, we should seek perception inthe simple substance and not in the composite or in the machine. (G6:609; AG 215)

It is easy to see why this is one of the better-known passages in theMonadologie. It contains a vivid imaginative thoughtexperiment that is presented in support of an anti-materialistconclusion, namely that perception is inexplicable by means of shapesand motions. Given that thought experiments along these lines havebeen popular in contemporary philosophy of mind it might seem naturalto suppose that Leibniz takes the thought experiment to provide aconclusive argument for his conclusion (it is sometimes referred to as“Leibniz’s Mill Argument”). Although this is not theplace to discuss the issue at length, we can say that Leibniz’sremarks on the exoteric/esoteric distinction suggest that this mightnot be the case. It is plausible to think that the passage is designedto appeal to people who rely heavily on the imagination in doingphilosophy; it could be a heuristic that will help motivateLeibniz’s thesis that perception is a property of simplesubstances and not of bodies, not a rigorous argument for thisconclusion .

As the discussion of Leibniz’s Mill Argument suggests, it is notalways easy to recognize when Leibniz is using an exoteric strategy.Another place where an exoteric strategy might be at work is in one ofhis most frequent “arguments” for the theory of simplesubstances. Consider the first section of thePrincipes de laNature et de la Grace and the first three sections of theMonadologie:

[1]

“A substance is a being capable of action. It is simple orcomposite. Asimple substance is that which has no parts.A composite substance is a collection[l’assemblage] of simple substances, ormonads.Monas is a Greek word signifying unity, orwhat is one. Composites or bodies are multitudes; and simplesubstances—lives, souls, and minds—are unities. There mustbe simple substances everywhere, because, without simples, there wouldbe no composites” (G 6:598; AG 207).

[2]

“1. TheMonad, which we shall discuss here, isnothing but a simple substance that enters intocomposites—simple, that is, without parts. 2. And there must besimple substances, since there are composites; for the composite isnothing more than a collection, oraggregate [un amas, ouaggregatum], of simples. 3. But where there are no parts, neitherextension, nor shape, nor divisibility is possible. These monads arethe true atoms of nature and, in brief, the elements of things”(G 6:607; AG 213).

These texts contain important similarities and differences. In[1] he speaks of “composite substances”, which he alsodescribes as “bodies”, while in[2] he speaks only of “composites”. Setting these differencesaside for the moment, both texts contain a version of what has beentermed the “grounding argument” for simple substances.Taken at face value, the texts suggests the following argument:

1. composites exist
2. a composite is a collection of simple substances
3. therefore, simple substances exist

The reader seems invited in these passages (particularly in[1] and the first two sections of[2]) to conceive of the relation between simples and composites in astraightforward and intuitive way. If you have a dozen eggs, forexample, you must have twelve individual eggs. Trying to argue thatone could have a dozen eggs without having any individual eggs seems ahopeless task indeed. The argument also initially lends itself to akind of physical atomism. If one thinks that tables and chairs, forexample, are collections of indivisible physical atoms, then theargument is once again intuitive and difficult to deny. It becomesclear in the third section of text[2] that the relation between composite and simple cannot be quite thisstraightforward because the simples are not extended. Leibniz alsomakes this point in the section that follows[1] in thePrincipes de la Nature et de la Grace. But somethinglike the intuitive picture remains. There are composites (bodies).Composites are collections of simples. If you put a bunch of simplestogether you get a composite. It is natural to think that the relationbetween simples and composites is understood on the model of part andwhole. Simples are the parts that compose wholes (bodies).

Leibniz’s considered view is far more nuanced and lessstraightforward than texts[1] and[2] suggest. First, Leibniz does not think monads compose bodies in themanner of a part/whole relation. As he explains elsewhere, a part of awhole must be “of the same sort” as the whole (G 3:591).Monads and bodies are not of the same sort because only the latter areextended. This implies that the parts of an extended body mustthemselves be extended. Leibniz does assert on a number of occasionsthat bodies are aggregates of monads (or simple substances). However,he has a technical conception of an aggregate (see Lodge 2001).Suppose, for example, that there were a carton of twelve eggs sittingon a table. This alone would not imply that there was an aggregate ofeggs, strictly speaking. For there to be an aggregate of eggs therewould need to be at least two eggs that are perceived by a mind asbeing one thing (i.e., by perceiving them as a unity). So you cannotmerely add together a bunch of eggs to get an aggregate of eggs.Similarly, you cannot merely add together a bunch of monads to get anaggregate of monads. You only have an aggregate if there is a mindthat perceives the individuals as constituting one thing. The precisedetails of how one should understand Leibniz’s claim that bodiesare aggregates of monads is a matter of scholarly controversy that weneed not engage here. It will suffice to make the following points.The fact that bodies are aggregates of monads implies that bodiesdepend ontologically on monads but it does not imply that the relationbetween monads and bodies is a part/whole relation. As Leibnizexplains to De Volder,

properly speaking, matter isn’t composed of constitutiveunities, but results from them…substantial unities aren’treally parts, but the foundations of phenomena. (G 2:268; AG 179)

Once one becomes aware of Leibniz’s technical notion of anaggregate and of certain aspects of his conception of the part-wholerelation, it becomes less clear exactly how the “groundingargument” in texts[1] and[2] is supposed to work. The intuitive appeal of the argument seems todepend, at least in part, on assuming a straightforward account of therelation between bodies and monads that Leibniz does not actuallyendorse. Leibniz seems to encourage this oversimplified account of therelation by omitting an explanation of his notion of an aggregate andof his account of the part-whole relation, among other things. Thissuggests that Leibniz is not trying to provide a fully rigorousargument for the existence of simple substances or a full explanationof the relation between monads and bodies in theMonadologieor thePrincipes de la Nature et de la Grace. What Leibniz isdoing, one might think, is helping his readers attain a preliminarygrasp of the relation between bodies and simple substances—tohelp them recognize that simple substances provide some kind ofontological grounding for the world of bodies. By introducing the viewin the form of a simple and intuitive argument Leibniz helps tomotivate the radical idea that an infinity of immaterial mind-likesimple substances exist. The reader will thus be more likely to takethe view seriously enough to consider the further elaborations of thetheory that are presented in the remainder of the texts. This is notto deny that Leibniz might have had a fully demonstrative“grounding argument” for the existence of simplesubstances, or that he wanted the fully demonstrative argument to beconsistent with the versions of the argument that are presented intexts[1] and[2]. The point is that Leibniz omits too many essential distinctions anddetails for even a very discerning reader to be able to reconstruct ademonstrative argument merely on the basis of texts[1] or[2]. On this readingsignificant portions of theMonadologie and thePrincipesde la Nature et de la Grace are exoteric in content and form.They serve to introduce some of the central features ofLeibniz’s metaphysics while omitting many important details(more details are omitted in the latter text, as we will soonsee).

Let us now consider one notable difference between theMonadologie and thePrincipes de la Nature et de laGrace. In thePrincipes de la Nature et de la GraceLeibniz speaks of “composite substances” while in theMonadologie he only speaks of “composites”. Thedifference is puzzling. In theMonadologie Leibniz istypically taken to be presenting a strictly monadological metaphysicsaccording to which simple substances are the only finite substances.Bodies exist and animals exist, but they are not substances (roughlyspeaking he thinks that an animal is a dominant monad and its organicbody, which is itself an aggregate of monads). A number of textssuggest that neither bodies nor animals are true unities, and only atrue unity (anunum per se) can qualify as a substance,strictly speaking. Any reality that bodies and animals possess is insome way derivative of the reality of simple substances. The obviouspuzzle is that Leibniz speaks of simpleand compositesubstances in thePrincipes de la Nature et de la Grace. Whatare we to make of these seemingly divergent claims?

One way of accounting for divergent claims in different texts is tosay that Leibniz had different views on the issue over time. There isno question that Leibniz’s views on substance changed to somedegree over the course of his career (exactly how much they changed isone of the most contentious issues in Leibniz scholarship). However,the developmental strategy is more difficult (though not impossible)to deploy in the present case because both texts were written aroundthe same time in 1714. Another possibility (suggested in the secondaryliterature) is that Leibniz is exploring different theories ofsubstance at this point in his career. Though he is tempted by astrictly monadological metaphysics (as presented in theMonadologie), he is also considering an ontology thatcountenances the existence of simple substances and corporealsubstances (where corporeal substances are “animals” asdescribed in the previous paragraph). Leibniz is laying out thislatter theory inThe Principes de la Nature et de la Grace(see Hartz 2007). There are someprima facie reasons forresisting an interpretation along these lines (though it cannot beconclusively ruled out). First, Leibniz does not describe himself as a“theory pluralist” with respect to substance. As we haveseen, Leibniz consistently refers to his philosophy as a (single)system. This is one of the things that make it amenable to thegeometric model of demonstration. When Leibniz addresses the factthat he has not unfolded his entire system in a single work, heemphasizes that this is not because he has not thought the system allthe way through. In one of his less modest moments he writes toBurnett, for example:

I never write anything in philosophy that I do not treat bydefinitions and axioms, though I do not always give it thatmathematical air, which puts people off, for one must speak in afamiliar manner [familierement] to be read by ordinarypeople…I would even dare to say that I have establishedsufficiently in all matters of thought what is most fundamental tothem, and that I no longer have any need to reason about them. Thuswhat you wish for me to do was already done a long time ago. I havequite satisfied myself on nearly all matters of reasoning. (10December 1705 letter to Burnett; G 3:302–3)

Another place where Leibniz emphasizes the systematicity of hisphilosophy is in his correspondence with Des Bosses:

My views certainly are connected with each other in such a way that nolink can be removed without the chain’s being broken. From thevery consideration of possible worlds and God’s choice, itfollows both that he has chosen the best and that he has chosen itwith one decree, whose object, obviously, is the chosen world.(October 1708 letter to Des Bosses, LR 113)

If only the attribute of incomprehensibility were proper to God alone!Then, our hope of knowing nature would be greater. But it is all tootrue that there is no part of nature that could be known perfectly byus, and the very interconnection of things proves this. No creature,however elevated, can perceive distinctly or comprehend the infiniteat the same time; but, on the contrary, whoever comprehends even onepart of matter likewise comprehends the whole universe on account ofthe same interconnection I mentioned. My principles are such that theycan hardly be separated one from another. Whoever knows one well,knows them all. (7 November 1710 letter to Des Bosses, LR 189)

More could be said about the context of these passages and exactly howthey should be interpreted. At the very least, however, these texts donot suggest that Leibniz saw himself as unsure about which theory ofsubstance to endorse. That being said, Leibniz wrote a considerableamount on the theory of monads and bodies between 1710 and 1714. DidLeibniz’s views on substance evolve during those interveningyears?

To answer this question one would need to delve deeply intoLeibniz’s long and fascinating correspondence with Des Bosses(as well as other texts). This is obviously not the place to providesuch an investigation, but we can briefly summarize a standardinterpretation of one of the central moments of the correspondence(see Look and Rutherford’s introduction [2007] to theLeibniz-Des Bosses Correspondence, xlix–lxxviii). As a Jesuitpriest, Des Bosses was interested in determining whetherLeibniz’s philosophy could provide an adequate ontologicalframework for the doctrine of transubstantiation. The central point ofcontention in their discussion of this issue concerned the reality ofcorporeal substance. Did Leibnizian corporeal substances meet thecriteria for being a substance in the strict sense of the term? On amonadological view a corporeal substance (or animal) is a dominantmonad united with an organic body, which is itself an aggregate ofsubordinate monads. The “union” of a dominant monad andits organic body consists in certain harmonious perceptual relationsthat obtain between the dominant monad and the subordinate monads ofthe organic body. This rather weak notion of union is not sufficientto make the dominant monad and its organic body truly one being. Thisimplies that a corporeal substance is not a substance strictlyspeaking because it does not possessper se unity. Des Bossesthought that this reductive view of corporeal substance did notprovide a robust enough conception of the reality of bodies toproperly ground the doctrine of transubstantiation. In response to DesBosses’ concerns Leibniz developed the notion of a substantialbond (vinculum substantiale). This substantial bond(superadded by God) could serve as a kind of metaphysical glue unitingthe dominant monad and the subordinate monads of an organic body.Leibniz told Des Bosses that the only way for a corporeal substance tobe aper se unity would be through one of these substantialbonds. Arguably, Leibniz did not endorse the theory himself; he toldDes Bosses that he preferred the more ontologically parsimoniousversion of the theory of monads (letter of 16 June 1712; LR 255).

The correspondence with Des Bosses has thus been taken to providesupport for the interpretive thesis that Leibniz’s matureontology of finite substance countenances the existence of simplesubstances exclusively (but see Garber 2009 for an opposing view). Thecorrespondence also shows, importantly, that the mere occurrence ofthe word “corporeal substance” in a text does notimmediately imply that Leibniz takes corporeal substances to besubstances, strictly speaking. These conclusions might helpresolve the apparent tension between Leibniz’s remarks onsubstance in theMonadologie and thePrincipes de laNature et de la Grace. The text of theMonadologie moreaccurately reflects Leibniz’s considered position because itonly characterizes simple substances as “substances”. ThePrincipes de la Nature et de la Grace, in contrast, is lessrigorous on this issue (more exoteric) because it uses the term“composite substance” when composites are not substances,strictly speaking (Rutherford 1995: 281–2).

But why would Leibniz use a term like “compositesubstance” in thePrincipes de la Nature et de la Graceif it did not accurately reflect his considered position? Here is onepossible answer. In presenting his theory of simple substances Leibnizwas concerned to avoid a fundamental misunderstanding. Themisunderstanding is that if the only true substances are unextendedsimple substances, then bodies must be mere illusions. Leibniz doesnot think that bodies are mere illusions. His view of bodies (from theperspective of the theory of monads) is, roughly, that they are“real but not fully real”. To adequately graspLeibniz’s view one must understand that his ontologycountenances different levels or degrees of reality. Simplifyingthings considerably, these degrees range from the ideal (the leastreal) to the phenomenal (mid-grades of reality) to the level of monads(the most real). Bodies fall within the purview of the phenomenal:they aremore real than entities that are purely ideal (e.g.,space) butless real than simple substances. Bodies areaccorded an enhanced degree of reality (in comparison to merely idealentities) because they are well founded on the reality of monads. Theprecise nature of this “well founding”—and ofLeibniz’s ontological scheme more generally—is acomplicated and controversial matter. The nuanced framework (howeverone might fill in the details) does not lend itself to astraightforward and intuitive presentation in several paragraphs oftext (see Whipple 2020 for a more detailed account).

One can reasonably view thePrincipes de la Nature et de laGrace as one of the most exoteric presentations ofLeibniz’s theory of monads. In the text he omits nearly all ofthe details of his nuanced ontological scheme. He describes bodies as“composite substances” so that his reader will recognizethat both simple substances and bodies are “real”. Byoveremphasizing the degree of reality that he grants bodies he is ableto introduce the theory of monads in a way that makes it appear lessfar removed from received opinions. It also helps avoid the seriousmisunderstanding that bodies are mere illusions—amisunderstanding that one could easily fall into in the absence of afull presentation of Leibniz’s ontological scheme.

This very brief sketch of an “exoteric resolution” of thetextual discrepancy between Leibniz’s use of the word“substance” in theMonadologie and thePrincipes de la Nature et de la Grace provides an alternativeto the “developmental” and “two theory”readings of the relevant passages mentioned earlier. It suggests amore general moral for Leibniz scholarship. Whenever one is faced withtexts that appear to provide conflicting remarks on an issue, it isimportant to consider whether an exoteric strategy that could resolvethe apparent conflict might be at work. It is not easy to determinewhen an exoteric strategy is at work given that Leibniz rarely flagsthe features of his works that are exoteric within the worksthemselves. One must consider Leibniz’s general remarks onexoteric strategies along with any additional texts that explicitly orimplicitly bear on the passages in question. It is only once all ofthese texts have been examined that one can argue that a particularinterpretive hypothesis is the best all things considered. In somecases an esoteric/exoteric interpretation will be the most plausible;in other cases it might be more plausible to view Leibniz as havingchanged his views over time, or as having not fully resolved adifficult problem, among other possibilities (see Whipple 2010 fordiscussion of a problem where it is particularly difficult to discernthe most plausible interpretation).

7. Summary

Throughout his career Leibniz distinguished between esoteric andexoteric modes of presentation in philosophy. He endorsed the esotericmode, which was modeled closely on the Geometrical model ofdemonstration, as the ideal mode of presentation. Leibniz did someimportant preparatory work for an esoteric presentation of hismetaphysics in the 1670s and 1680s, but he never completed a work thatwas in strict accordance with the esoteric ideal. Although hecontinued to regard the geometrical model of demonstration as theideal, he thought it would be a mistake tointroduce hisphilosophy to people in the form of an esoteric treatise. This isbecause thecontent of his philosophy was highly esoteric; itinvolved a range of abstract principles and theses, many of which werefar removed from received opinions. He thought that if he were topresent his philosophy in a strictly esoteric manner people wouldmisunderstand it and summarily reject it. This is why exoteric textswere so important for Leibniz. They were designed to serve asintellectual stepping-stones that could help readers move fromreceived opinions to esoteric truth. In letters to trustedcorrespondents Leibniz explicitly describes his journal articles andtheEssais de théodicée as exoteric works. Buteven Leibniz’s letters to trusted correspondents such as DeVolder and Des Bosses fall short of the esoteric ideal. All ofLeibniz’s texts are exoteric to a certain degree, but some aremore so than others. They can be categorized as more or less exotericdepending on the degree to which they approximate the esoteric idealin form and content. It is difficult to provide this categorizationgiven that Leibniz never completed a strictly esoteric treatise.However, Leibniz’s general comments about the exoteric mode ofpresentation can help us form reasonable hypotheses about theimplicitly exoteric features of his texts. We have seen that Leibnizutilized a variety of complimentary exoteric techniques,including:

1. Selective omission: he omits the features of his philosophy that arefurthest removed from received opinions. In some cases it is possibleto infer the omitted views from a careful reading of the exoterictext; in other cases a supplementary work is required.

2. Surface reading vs. deep reading: the text admits of an intuitivesurface reading that can make his views seem closer to receivedopinions than they actually are. The texts are also compatible with amore rigorous but less straightforward reading; it may or may not bepossible to grasp the deeper meaning on the basis of the exoteric textalone.

3. Familiar language: he tailors his language to his audience so that itwill appear more familiar to them. For example, he uses Cartesianlanguage when he writes in the journals of Paris and the language ofthe schools when he writes in the journals of Leipzig.

4. Eclectic references: he appeals to the claims of well-regardedhistorical and contemporary figures to illustrate and motivate his owntheses.

5. Hypothesis: he presents a thesis as a hypothesis rather than providinga strict demonstration of the thesis, even if he is capable ofproviding the demonstration. He thinks that in some cases a readerwill be less hostile to a novel thesis if it is presented as ahypothesis.

6. Sensible analogies, metaphors, imaginative thought experiments,stories, and anecdotes: he utilizes these devices because they allowreaders that are accustomed to conceiving of things by means of thesenses and the imagination to attain an introductory understanding oftheses and principles that are abstract and distinctly conceivableonly through the intellect (not the senses or the imagination).

Some work identifying particular exoteric strategies has been done inthe secondary literature on Leibniz. However, much work remains to bedone. More detailed examinations of the exoteric features ofLeibniz’s works will help us more adequately determine whichtexts (if any) present his considered views and the extent to whichhis philosophy is systematic.

Bibliography

Primary Sources

Note that all quotes from untranslated sources listed below aretranslated by the author of this entry.

[A]

Sämtliche Schriften und Briefe, Darmstadt andBerlin: Berlin Academy, 1923–, (cited by series, volume, andpage).

[AG]

Philosophical Essays, Roger Ariew and Daniel Garber(trans.), Indianapolis, IN: Hackett, 1989.

[CP]

Confessio Philosophi: Papers Concerning the Problem of Evil,1671–1678. Translated and edited by Robert C. Sleigh, Jr. NewHaven, CT: Yale University Press, 2005.

[FC]

Lettres et opuscules inedits, Louis Alexandre Foucher deCareil (ed.), Hildesheim, New York: George Olms, 1975.

[G]

Die philosophischen Schriften von Gottfried WilhelmLeibniz, C. I. Gerhardt (ed.), Berlin: Weidman, 1875–1890(cited by volume and page).

[L]

Philosophical Papers and Letters, second edition, LeroyE. Loemker (trans.), Dordrecht and Boston: Reidel, 1969.

[LR]

The Leibniz-Des Bosses Correspondence, Brandon C. Lookand Donald Rutherford (trans.), New Haven, CT: Yale University Press,2007.

[LBr]

Briefwechsel, Hannover: Gottfried Wilhelm LeibnizBibliothek/Niedersächsische Landesbibliothek.

[NE]

New Essays on Human Understanding (Nouveaux essaissur l’entendement humain), Peter Remnant and JonathanBennett (trans.), Cambridge: Cambridge University Press, 1981 (thepagination of this work corresponds to that of the Academy edition Avi 6; thus only one reference is required).

[RA]

The Labyrinth of the Continuum: Writings on the ContinuumProblem, 1672–1686, Richard T. W. Arthur (trans.), NewHaven, CT: Yale University Press, 2001.

[SR]

De Summa Rerum: Metaphysical Paper,1675–1676. Translated and edited by G.H.R. Parkinson. NewHaven, CT: Yale University Press, 1992.

[T]

Theodicy: Essays on the Goodness of God, the Freedom of Man,and the Origin of Evil (Essais dethéodicée), E. M. Huggard (trans.), La Salle, IL:Open Court, 1985 (cited from G 4 by section number).

[WF]

Leibniz’s ‘New System’ and AssociatedContemporary Texts, Roger S. Woolhouse and Richard Francks(trans), Oxford: Clarendon Press, 1997.doi:10.1093/actrade/9780198248460.book.1

Secondary Sources

• Adams, Robert Merrihew, 1994,Leibniz: Determinist, Theist,Idealist, New York: Oxford University Press.doi:10.1093/0195126491.001.0001
• Antognazza, Maria Rosa, 2009,Leibniz: An IntellectualBiography, Cambridge/New York: Cambridge University Press.doi:10.1017/CBO9781139012805
• Brown, Stuart, 1996, “Leibniz’sNew SystemStrategy”, in Woolhouse 1996: 37–61.
• Curley, E. M., 1972, “The Root of Contingency”, inLeibniz: a Collection of Critical Essays, Harry G. Frankfurt(ed.), Notre Dame, IN: University of Notre Dame Press,69–97.
• Garber, Daniel, 2009,Leibniz: Body, Substance, Monad,Oxford: Oxford University Press.doi:10.1093/acprof:oso/9780199566648.001.0001
• Hartz, Glenn A., 2007,Leibniz’s Final System: Monads,Matter, and Animals, London: Routledge.doi:10.4324/9780203967966
• Lamarra, Antonio, 2009, “La Pensée Monadologiquede Leibniz dans la Théodicée: Problèmesd’Interprétation”, inL’idéede théodicée de Leibniz à Kant: héritage,transformations, critiques, Paul Rateau (ed.), Stuttgart: FranzSteiner Verlag, 11–21.
• Lodge, Paul, 2001, “Leibniz’s Notion of anAggregate”,British Journal for the History ofPhilosophy, 9(3): 467–486.doi:10.1080/09608780110072461
• –––, 2010, “The Empirical Grounds forLeibniz’s ‘Real Metaphysics’:”,LeibnizSociety Review, 20: 13–36. doi:10.5840/leibniz2010202
• Look, Brandon, 1999,Leibniz and the “VinculumSubstantiale”, Stuttgart: Franz Steiner.
• Look, Brandon C. and Donald Rutherford, 2007,“Introduction”, inThe Leibniz-Des BossesCorrespondence, New Haven, CT: Yale University Press.
• Melzer, Arthur M., 2014,Philosophy Between the Lines: TheLost History of Esoteric Writing, Chicago: University of ChicagoPress.
• Mercer, Christia, 2001,Leibniz’s Metaphysics: ItsOrigins and Development, Cambridge/New York: Cambridge UniversityPress. doi:10.1017/CBO9780511498268
• Nelson, Alan, 2005, “The Rationalist Impulse”, inA Companion to Rationalism, Alan Nelson (ed.), Oxford:Blackwell Publishing, 1–11. doi:10.1002/9780470996904.ch1
• Russell, Bertrand, 1937,A Critical Exposition of thePhilosophy of Leibniz, second edition, London: Allen andUnwin.
• –––, 1945,A History of Western Philosophy,and Its Connection with Political and Social Circumstances from theEarliest Times to the Present Day, New York: Simon and Schuster.[Chapter 11 on Leibniz is on pp. 581–596.]
• Rutherford, Donald, 1995,Leibniz and the Rational Order ofNature, Cambridge/New York, NY: Cambridge University Press.doi:10.1017/CBO9781139172776
• –––, 1996. “Demonstration andReconciliation: The Eclipse of the Geometrical Method inLeibniz’s Philosophy”, in Woolhouse 1996:181–201.
• Schepers, Heinrich, 2008, “Leibniz’s Rationalism: APlea Against Equating Soft and Strong Rationality”, inLeibniz: What Kind of Rationalist?, Marcelo Dascal (ed.),(Logic, Epistemology, and the Unity of Science 13), Dordrecht:Springer Netherlands, 17–35.doi:10.1007/978-1-4020-8668-7_2
• Whipple, John, 2010, “The Structure of Leibnizian SimpleSubstances”,British Journal for the History ofPhilosophy, 18(3): 379–410.doi:10.1080/09608781003779768
• –––, 2011, “Continual Creation and FiniteSubstance in Leibniz’s Metaphysics:”,Journal ofPhilosophical Research, 36: 1–30.doi:10.5840/jpr_2011_6
• –––, 2015a, “Leibniz and the Art ofExoteric Writing”,Philosopher’s Imprint, 15:article 35. [Whipple 2015a available online]
• –––, 2015b, “Leibniz on Substance andCausation”, inLocke and Leibniz on Substance, PaulLodge and Tom Stoneham (eds.), New York: Routledge.
• –––, 2017, “Leibniz on FundamentalOntology: Idealism and Pedagogical Exoteric Writing”,Ergo,an Open Access Journal of Philosophy, 4(11): 311–348.doi:10.3998/ergo.12405314.0004.011
• –––, 2020, “The Correspondence with DeVolder”, inLeibniz’s Key Philosophical Writings,Paul Lodge and Lloyd Strickland (eds.), Oxford: Oxford UniversityPress, 123–144. doi:10.1093/oso/9780198844983.003.0007
• Woolhouse, Roger S. (ed.), 1996,Leibniz’s “NewSystem” (1695), Firenze, Italy: L.S. Olschki.

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