the ontology of descartes

The Ontology of DescartesAuthor(s): Ivor LeclercSource: The Review of Metaphysics, Vol. 34, No. 2 (Dec., 1980), pp. 297-323Published by: Philosophy Education Society Inc.Stable URL: http://www.jstor.org/stable/20127501 .

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THE ONTOLOGY OF DESCARTES

IVOR LECLERC

I

V/NTOLOGY, as a special field of philosophical inquiry, has been con

siderably neglected in modern times, and it is thus not surprising that little attention has been paid to Descartes in respect of ontology, especially since he himself did not bring it into prominence in his

writings. His not having done so is quite in line with his characteris

tic procedure, which was not to engage head-on the fundamental posi tions or presuppositions which he was disputing, but rather to dis

tract attention from them so as to secure an unantagonistic hearing for his own theories.1 I shall argue that Descartes had an ontology,

which was not merely implicit, and that when we discern his ontology we can see his position in the basic areas?metaphysics, epistemol

ogy and methodology, philosophical psychology or theory of mind? to have been consistently determined by his ontology.

Descartes' ontology, I shall maintain, is essentially Neoplatonic. A pointer in this direction is constituted by the fact that Descartes was not only opposed to the reigning Aristotelian scholasticism, but

was part of the new movement of thought, originating in the fifteenth

century with thinkers such as Nicolaus Cusanus and growing steadily

during the sixteenth, the movement which gave birth to modern sci

ence and philosophy in the seventeenth century, to which Descartes

himself was to make such signal contributions. This movement rep

resented a swing away from the medieval Aristotelianism of the ante

cedent few centuries, and a return to the earlier tradition of Neopla tonism.

During the sixteenth century the focus of attention of this move

ment was increasingly on the philosophy of nature, and this resulted,

Review of Metaphysics 34 (December 1980): 297-323.

Copyright ? 1980 by the Review of Metaphysics

1 Cf. e.g., Descartes' statement to Mersenne (letter of 28 Jan. 1641): "I

hope that my readers will gradually get used to my principles, and recognize their truth, before they notice that they destroy the principles of Aristo tle." Ed. and trans. A. Kenny, Descartes: Philosophical Letters (Oxford: Clarendon Press, 1971), p. 94; C. Adam & P. Tannery, Oeuvres de Descartes (Paris: L. Cerf, 1897-1910).



298 IVOR LECLERC

in the first decades of the seventeenth century, in a new conception of

nature, of the physical, in opposition to the medieval Aristotelian con

ception of nature. This new conception had attained its most ad

vanced philosophical elaboration by the end of the second decade of the century by the French medical doctor, Sebastian Basso, in his

Philosophia Naturalis (1621).2 Basso was somewhat ahead of his contemporaries in taking the

radical step of rejecting the traditional metaphysical analysis of phys ical being into form and matter, maintaining instead that the physical is constituted by matter alone.3 He also more clearly than others at

the time appreciated some of the principal philosophical implications of this new conception of the physical. First, it entailed the elimina

tion of form from the physical, and therewith of all qualitative fea tures?a conception so radical at the time that even Basso did not

manage to hold it with complete consistency.4 Secondly, the elimina

tion of form from the physical also entailed the elimination of the prin ciple of agency and change from the physical.5 This, Basso held, was

completely consistent with the conception of "matter," this having

traditionally, in medieval thought, been held to be in itself entirely changeless. The conception of the physical as "matter," Basso saw,

entailed not only that one piece of matter is not different from an

other, qua matter?for matter, being devoid of form, can admit of no

difference of "kinds"?but also, being without any inherent principle of change, it is incapable of either augmentation or diminution in size,

i.e., of quantitative change. Matter, wherever encountered, is sim

ply in itself changeless matter. But?and this, for Basso and for the

new conception of the physical, was most important?while matter

was incapable of any internal change, qualitative or quantitative, there was nothing to prohibit its being subject to change of place, i.e.,

2 Sebastian Basso, Philosophiae Naturalis adversus Aristotelem

Libri XII. In quibus Abstrusa Veterum Physiologia restauratur, & Aristo telis errores solidis rationibus refelluntur. (Averianae: Petrum de la

Rouire, 1621). Basso describes himself on the title page as "Amicus Plato, amicus Socrates, sed magis arnica Veritas."

3 For a fuller account of this development see my The Nature of Physi cal Existence (London: Allen & Unwin; New York: Humanities Press, 1972), part 2, chaps. 7-11.

4 He included hot and cold among the primary features of material cor

puscles, which were otherwise entirely quantitative. 5 See pp. 299-300 below for an analysis of the theory according to which form constitutes the principle of agency and change in the physical.



THE ONTOLOGY OF DESCARTES 299

of locomotion, this being purely an external change of relations with

other parts or pieces of matter, not necessitating any change in them

per se.

Now when we look at this new doctrine of the physical from an

ontological point of view, it is evident that this conception of the phys ical as matter means that matter "is." That is, in the physical realm, "what is" or "what exists" in the primary sense, is matter. This doc

trine constitutes a profound change from the medieval view of the

status of matter, and more particularly from the traditional Neopla tonic view of that status. For in traditional Neoplatonism, matter

had a status the very opposite of "being," i.e., of "not-being"?or at

most a prope nihil. By contrast, Basso was now maintaining the po

sition of matter per se as "being." But while Basso's position was thus in sharp contrast to that of

traditional Neoplatonism in respect of the status of matter, Basso's

position did not involve a divergence from traditional Neoplatonism in

ontology, i.e., in the basic doctrine respecting "being": this is that

"being" stands in essential contrast to, and excludes, "becoming"?a

doctrine, as we shall see, of crucial significance.6 Basso's divergence was in respect of the metaphysics which follows from this ontology: that is, first, in respect of what is to be identified as constituting "a

being," "a res," "a primary existent entity"; and secondly, in respect

of the analysis of "becoming"?for, from the earliest times, the physi cal had been regarded as essentially involving "becoming."

In traditional Neoplatonic metaphysics, what was identified as a

primary "being" was "form," including "form in enaction, i.e., soul."7

The metaphysical analysis of physical being was of it as composite of

form and matter (soul and body). But it was not this composite

which, per se, was "being," for in the basic Neoplatonic position

"being" pertains strictly only to form (soul) and not at all to matter

(body); the composite physical entity "is" or "exists" at all only by vir tue of its form or soul. Further, in this metaphysics, since form is

6 The Neoplatonic ontology derives from Plato, who in this respect goes back to Parmenides. In this tradition from Parmenides, "being" is conceived as fundamentally contrary to "becoming"; this means that "being" essentially connotes changelessness, excluding any kind of process of "com

ing-into-being." In response to the metaphysical issue of the identity of "that which is," Plato put forward the theory that "being" had to be that of the eide, Ideas or Forms, since these alone are without change. 7 Cf. Plotinus Enneads 5.2.1.



300 IVOR LECLERC

"being," and "being" excludes "becoming," the act of form cannot in

volve "becoming"; so that the "becoming" of the physical entity (its motus, constituted by qualitative and quantitative change as well as

change of place) was analyzable as consequent upon and as the result

ant of the act of the form or soul.8

Basso developed a quite different metaphysical analysis of the

physical on the basis of the same essentially Neoplatonic ontology,

i.e., theory of "being." In Basso's metaphysics, what was identified

as physical being was not, as in traditional Neoplatonism, a composite of form and matter, but matter alone, without any form. Basso held

that matter could consistently be regarded as "being," in accordance

with the Neoplatonic doctrine of "being," since matter is in itself

changeless and thus excludes "becoming." But, since matter is de

void of form and thus of act and of any internal principle of change, Basso required a different metaphysical analysis of "becoming" from

that of traditional Neoplatonism. Matter, Basso held, while in itself

changeless, is capable of undergoing locomotive change, and by vir

tue of this change of place it is possible for various groupings or ag

gregations of parts or pieces of matter to "come into being." That

means that there is "becoming" or "coming-into-being" in the physi

cal, but that this pertains to pluralities or groups and not to the unit

pieces or parts of matter, for these per se are simply in themselves

changeless "beings."

II

This brief analysis of Basso's metaphysics of nature and of its on

tological basis has been given because of its fundamental relevance to

Descartes. For in 1625 Descartes returned to Paris, then one of the

liveliest centers of interest in the new theory of the physical or nature as matter which had come to be developed in opposition to the reign ing Aristotelian doctrine of nature. It was there that Basso and his circle had been active for many years (despite the ban imposed on the

teaching of this theory by the Church) and where others, such as Gas

sendi, were then manifesting an interest in the new theory. Des

8 In this position the physical is not per se "being"; "being" pertains strictly to the "form" or "soul" of the composite entity, so that the composite physical entity "is," or "has being," in a derivative sense.




cartes remained in Paris and its environs for some four years, during which time he had evidently immersed himself in physical theory? testified by his letter of 8 October 1629 to Mersenne, conveying the

information that he had attained clarity as to the foundations of his

physical system. This system, fully developed, appeared in print only in 1646 in his Principles of Philosophy, but the fundamentals of

it were presented in his treatise, Le Monde, which had been com

pleted in 1633, but then suppressed. Descartes' system can readily be recognized as a response to a

number of basic philosophical problems and difficulties involved in the new philosophy of the physical as developed by Basso and by others at that time. Scientific inquiry had led these thinkers to the concep tion of matter as being ultimately constituted of atomic corpuscles.9 The philosophical difficulties involved in the concept of atomism were

far from having been unappreciated at that time, but Descartes saw

clearly that they were indeed crucial in regard to the new theory of the physical as matter.10 For, as he put it in a letter to Mersenne, "an atom can never be conceived distinctly, since the very meaning of

the word involves a contradiction, that of being a body and being di

visible."11 That is, the connotation of "body" necessarily includes

"extension," and every extension is, mathematically considered, di

visible, indeed ad infinitum, which contradicts the concept of "atom."

This meant to Descartes, not that the new theory of the physical as matter was unacceptable, but that there was a fatal contradiction

involved in how "matter" was being conceived by Basso, Gassendi, and others. This contradiction, Descartes maintained, arose from

the acceptance by these thinkers of the traditional presupposition,

going back to the earliest Greek thought, that a physical existent is

necessarily and essentially "bodily." The proponents of the new the

ory of the physical as matter had simply carried over that presupposi

tion, conceiving "matter" as essentially bodily stuff. It took the sin

gular philosophical penetration of Descartes to realize that the

conception of matter as bodily involved a contradiction. The concept of the physical as matter entailed that matter was extensive. The

concept of "body" also entails its being extensive. But it does not fol

low that, because every body must be extensive, therefore every ex

9 See my The Nature of Physical Existence, chap. 11. 10

Ibid., chaps. 14-15. 11

Kenny, p. 79; Adam & Tannery, 3: 191.



302 IVOR LECLERC

tensiveness must be that of a body. And further, it is entailed in the

concept of "body," and particularly of "atomic body," that a body has

"bounds," but the concept of "a thing which is extensive" does not en

tail its having bounds, since "extensiveness" as such does not entail

"bounds."12 Therefore, Descartes concluded, the only way to have a

consistent conception of the physical as matter, is to conceive matter

as having the sole essential feature of "extension." This led to the

further conclusion that, since matter is physical res or substance, it

could not consistently be maintained that there is one "kind" of physi cal res, namely matter, but that this is plural, i.e., that there are an

infinite plurality of unit material beings; on the contrary, since exten

sion does not entail bounds, matter per se must be without bounds

and must thus be infinite or interminate. That is to say, matter as

extensive necessitates that there can be only one physical being: mat

ter must constitute one res extensa.

It is quite clear from Le Monde and Descartes' subsequent

writings that he completely accepted the new metaphysical theory of nature or the physical as matter. His difference from the other ad

herents of this doctrine was in respect of how he conceived "matter":

that the metaphysical nature of matter consisted solely in its being "extensive," which meant that there could be only one interminate

res extensa. But this did not affect his agreement with Basso and

others about the metaphysical nature of matter, more particularly that matter in itself is without any form, and that it is thus devoid of

any internal agency, which entailed that matter is in itself change less. This meant that Descartes accepted that matter is physical

"being," excluding "becoming." Evidently therefore Descartes ac

cepted the basic Neoplatonic ontology. It is not the case however, as

we shall see, that his acceptance of this ontology was merely implicit, because the entire metaphysical doctrine of the physical which he de

veloped, as well as that of the soul, and of perception, knowledge, etc., was consistently, and moreover consciously so, in accord with

the Neoplatonic doctrine of "being." That is, Descartes keenly ap

preciated what was logically entailed in that ontology in respect of

metaphysical theories.

In his conception of the physical as matter, inherently extensive, Descartes was evidently in the Neoplatonic tradition deriving from

12 Cf. Meditations 2, trans. E. Haldane & G. R. T. Ross, 2 vols. (Cam bridge: Cambridge University Press, 1911), 1:151; Adam & Tannery, 7: 26.




Nicolaus Cusanus, which had influenced many in the sixteenth and se

venteenth centuries, of the world as explicatio Dei.13 Cusanus had

held that God, the infinite, the absolute perfection, had created a per

fect physical world, this perfection being manifest in and constituted

by its fundamental feature or essence of interminate, mathematical,

extension. Descartes integrated this conception with the new seven

teenth-century metaphysics of nature as matter: the physical is mat

ter, interminately extensive, and qua extensive, it is essentially

mathematical.

With this conception of matter as essentially mathematical Des

cartes saw that he had the solution to a crucial problem which had

come to the fore in the debates over atomism, namely the problem of

the relation of the physical and the mathematical. It had been ar

gued, as we have seen, that since extension is, mathematically con

sidered, divisible ad infinitum, this contradicts the concept of "atom." Descartes saw that the attempt to avoid this contradiction

and save atomism, made by Gassendi for example, by regarding the

mathematical as purely mental, not inherent in the physical per se,

had the consequence of rendering measurement of the physical com

pletely incomprehensible, and thus leaving without foundation the new science of mechanics of Galileo and others, for this science was

based on measurement. This new science required as its metaphysi cal foundation, the conception of the physical as essentially and in

herently mathematical. It is by virtue of matter being mathematical,

he had held in Le Monde (chap. 6), that it is perfectly knowable. Thus with this metaphysical conception of matter it was fully intelligi ble why the new mathematical physics provided genuine knowledge of the nature or essence of the physical. It was on the basis of this

metaphysical conception of "matter" that Descartes maintained, in

his Principles of Philosophy: "That I do not accept any other princi ple in Physics than in Geometry or abstract Mathematics, because all

the phenomena of nature may be explained by their means, and sure

demonstration given of them."14

This unification of Descartes' metaphysics of nature and his

metaphysics of knowledge was grounded in his Neoplatonic ontol ogy. In this doctrine "being," as excluding "becoming," is change

13 See my The Nature of Physical Existence, chaps. 5-6. 14 Descartes, Principles of Philosophy, pt. 2, princ. 64; Haldane &

Ross, 1: 269; Adam & Tannery, 8: 78.



304 IVOR LECLERC

less. Descartes held that physical "being" as matter is essentially

mathematical, and is thereby in itself homogeneous and unvarying, not differing anywhere in respect of its mathematical character?the

same mathematical principles holding throughout?this being the basis of its changelessness; and as mathematical, it is infinitely divisi

ble?but not actually divided. It was, further, this changeless, un

varying mathematical character of matter as physical "being" which

rendered it knowable. For, as Plato had insisted, there could be true

knowledge only of what is in itself changeless, and this requisite was

provided by the changeless mathematical character of matter. That

the physical as matter should be thus conceivable and knowable with

such admirable consistency, evidently was compelling justification to

Descartes for the soundness and truth of this metaphysical concep

tion of the physical and of its ontological basis. On this basis Descartes was able to make further crucial develop

ments in his philosophy of nature. So far he had the conception of

physical being as matter, in itself changeless mathematical exten

sion. But phenomenally nature clearly manifests change; and indeed

change had antecedently, back to the Presocratics, been regarded as

intrinsic to and even of the very essence of the physical or nature.

What was more, the new developing science of nature in his day was a

mechanics, a mathematical inquiry into the motion of bodies. Now in

Descartes' conception of the physical as matter, there was neither

motion nor bodies; matter was in itself changeless and one. How

then was the fact of motion, i.e., change in respect of place, and a plu

rality of bodies, to be reconciled with that conception of the physical as matter? Are they at all capable of derivation from matter? How

could the one matter become plural when it was in itself changeless

"being," without any "becoming" at all?

Descartes' resolution of this problem was grounded in the Neo

platonic ontology. His predecessors, such as Basso, had seen that

the conception of physical being as matter, in itself changeless, while

ruling out any qualitative change or alteration and any quantitative

change such as diminution or augmentation in size, consistently ad

mitted change in respect of place, i.e., locomotion, for this did not en

tail any change in the material being itself. The philosophical issue then was, how did this locomotive change occur? This is a fundamen

tal philosophical problem affecting all varieties of the doctrine of the

physical as matter, that of a plurality of material atoms as well as that

of a one material res extensa. For the point is that material "being,"




in itself changeless and therefore devoid of "becoming," was thus without any inherent principle of agency, and could accordingly in no

way originate the locomotion. Locomotion of the physical had there

fore necessarily to result from an agency beyond the physical itself.

Basso, Gassendi, and others saw that there was only one possible can

didate for that agency, namely God.

With this Descartes fully agreed, and was clear, moreover, that

this view was not to be rejected as an instance of the fallacy of a deus ex machina?it would exemplify that fallacy if God were conceived as originating the motion by an impetus which itself involved locomo tion. Descartes held that God as the agent whereby there is locomo tion in the physical or matter is conceivable with complete consist

ency in terms of the Neoplatonic ontology. In this, as we have seen, "act" is conceived as strictly in contrast

to the change involved in "becoming";15 the latter involves "motion"

whereas the former does not. Descartes explicated this distinction

by saying that motion (more particularly locomotion) "is the transpor tation and not either the force or the action which transports."16 This meant that "the motion is always in the mobile thing, and not in that which moves: for these do not seem to me to be accurately

enough distinguished."17 That is to say that motion "is a mode of the mobile thing," a manner in which the mobile body exists?i.e., as

moving, as opposed to being at rest. The failure to distinguish "mo

tion" and "action" most commonly occurs in respect of a the impinge ment of a moving body on another: it is supposed that this impinge ment entails that the moving body "acts on" the other, "actively

putting" the other body into motion. Strictly, however, that body or

piece of matter is without any "action" of its own: it merely is "in mo

tion," and this motion is a "mode" of the body. It follows therefore that "a motion, being a mode of body, cannot pass from one body to

another."18 The conclusion is that an "action"?which is not to be

found in matter?is necessary to put the other body into motion.

Now in the Neoplatonic doctrine?at least that of the Augustin ian tradition?God is an acting being, and moreover a being whose

15 See above pp. 299-300. 16

Descartes, Principles of Philosophy, pt. 2, princ. 25; Haldane &

Ross, 1: 266; Adam & Tannery, 8: 53-54. 17

Ibid. 18 Descartes in a letter to Henry More, August 1649; Kenny, p. 258;

Adam & Tannery, 5: 404.



306 IVOR LECLERC

acting is creating. Further, in this Neoplatonic doctrine?explicitly accepted by Descartes?God's acting is essentially thinking, which

means that God creates by thinking. For the moment the important point here is that thinking is "acting," and that it does not involve any

movement in itself. In creating matter, however, God has to create

it either at rest or in motion?Descartes makes it clear that this en

tails that "more action is not required for movement than for rest," since God being perfect and thus constant, his acting is constant.19

Now the phenomenon of motion in nature makes evident that God

creates matter partly at least in motion. Moreover, phenomenally, the motion in nature is not uniformly the same: motion differs in dif ferent parts of matter. Further, there is no necessity that motion

should be everywhere the same; there is only the necessity that,

since God's action is constant, the totality of motion in nature should

be constant.

The foregoing considerations would furnish a satisfactory solu

tion to the problem of motion of material atoms. But Descartes had

found it necessary to reject the conception of atomism in favour of a

conception of matter as a one res extensa. This entailed, however, that Descartes was without any bodies to be moved, which meant

that Descartes was faced with the metaphysical problem of how bodies could be conceived as derivable from a res extensa which is

one, changeless, uniform, homogeneous, interminate. Descartes' so

lution had the elegant simplicity beloved of mathematicians. Since matter is in itself changeless and without action, motion had neces

sarily to be provided by God's creative action. God, by putting dif ferent parts of matter into differential motion, thereby brought bodies into existence. That is to say, according to Descartes' theory,

"body" is to be understood as a part of res extensa which is moving

differentially with respect to other parts of matter. As Descartes

put this: "By one body or by a part of matter I understand all that which is transported together," that transportation constituting "mo

tion," which is "the transference of one part or one body from the vi

cinity of those bodies that are in immediate contact with it, and which we regard as in repose, into the vicinity of others."20

19 Descartes, Principles of Philosophy, pt. 2, princ. 26 (heading); Hal

dane & Ross, 1: 266; Adam & Tannery, 8: 54. 20


Ross, 1: 266; Adam & Tannery, 8: 53-54.




This provides a consistent conception of "body" as not identifi

able with "matter" per se?in contrast to the doctrine of material

atomism. In Descartes' theory "bodies" are derivative from matter

through differential motion. Thus bodies are "material" as being

parts of res extensa without their being, metaphysically considered,

"matter per se." In other words, Descartes maintained that to be

"body" and to be "matter" are not equivalent, as the doctrine of ma

terial atomism entailed: to be "body" implied having definite bounda ries constituting its length, breadth, and depth, whereas "matter"

per se does not entail any such boundaries, but only the possibility of such boundaries arising within matter?a possibility which, in Des

cartes' theory, is actualized through motion. Thereby Descartes

had, upon the basis of the Neoplatonic ontology, a metaphysical con

ception of the physical as in itself changeless matter, a consistent

metaphysical explanation of the science of physics as it was in his day, the science of bodies in motion, and also provided the metaphysical

ground for that science, as essentially mathematical, constituting a

genuine knowledge of the physical. Without doubt this was an ac

complishment of great philosophical genius.

Ill

In the new metaphysical doctrine of the physical as matter, since

matter is in itself changeless and without agency, there is no need in the physical for form, as Basso had seen?for matter could not admit

differences of "kind"?or for soul as the principle of change and

agency. Descartes, in accepting the new conception of the physical as matter, accepted also those necessary implications. But he was

the first to appreciate with full clarity that the doctrine of the physical as matter necessitated a very thoroughgoing rethinking of the basic

philosophical issues, for that doctrine entailed a whole range of new

metaphysical, epistemological, anthropological, and other concep tions.

Antecedent philosophy, both classical Neoplatonism and medie val Aristotelianism, had maintained that, as far as the created physi cal world was concerned, form had the ontological status of the princi ple of "being" of the physical. Now that, in the new position, matter had been accorded the full ontological status of physical "being" per se, and the conception of "substantial form" had been extruded from



308 IVOR LECLERC

the conception of the physical, the wider philosophical issue arose

whether form had to be simply dismissed as an unnecessary meta

physical conception. Now thinkers such as Basso and Descartes who

had accepted the new theory of the physical were, as noted earlier, in

the Neoplatonic tradition. That is to say, they adhered to the Neo

platonic ontology, but modified the Neoplatonic metaphysics where

necessitated by the new conception of the physical as matter. In par

ticular this was the case with respect to form. In traditional Neopla tonism, form had been identified with soul. Descartes, more fully than others, saw that the conception of the physical as matter, entail

ing the extrusion of form and soul from the physical, implied the ne

cessity of according to soul the metaphysical status of an independent "being" or res. That is, the new doctrine of the physical as matter

entails a metaphysical dualism.

Descartes' solutions to the problems involved in this metaphysi cal dualism were grounded, as I shall seek to show, in a clear percep

tion of metaphysical implications involved in the, Neoplatonic on

tology. One problem which immediately arose was that of the interrela

tion of soul and matter (body). The issue, in the new position, was

different from that facing traditional Neoplatonism. In the latter, soul was conceived as necessarily interrelated with the physical, as

the principle of its "being" and of its motion and change.21 Further,

in that position, the physical is, metaphysically considered, a compos

ite unit of soul and body (matter), with these two constituents being,

ontologically, different?i.e., soul is "being," while matter is "not

being." In the new position the physical is matter, i.e., ontologically

considered, "being." But as thus itself "being," matter no longer has

the status of the substrate of form; it is itself the physical res, with

the essential feature of mathematical extension. The new position,

however, retains the traditional Neoplatonic conception of soul as

"being"?for Descartes the one certainty, withstanding all doubt, is

that cogito ergo sum?which entails that soul has to be metaphysi

cally regarded as a completely separate "being." But what does that

metaphysical distinction and separation entail with regard to the rela

tionship between soul and body (matter)? This dualism, Descartes saw, entails a somewhat different meta

21 That is, in the created sensible world of nature.




physical conception of soul from that of traditional Neoplatonism. For with matter as "being," in itself changeless, there could be no

need for soul as a principle of change in the physical as previously

maintained. That previous need had determined the conception of

soul, for the conception of the physical as in change (motus, Kivqcri?) necessitated a conception of soul as the principle of this change?that

constituting growth and development, the change involved in the vital motions of breathing, digestion and other vegetative functions, as well as change of place or locomotion. In man, as well as being the

principle of the vegetative and other motive features, soul was also

the agency whereby there is sensation, perception, feeling, and rea

son, i.e., thought. In the new position, all the changes in the physical were exhaustively analyzable in terms of locomotive change alone, which meant that any agency of the soul concerned with vegetative and other features of physical things was completely otiose. This left soul with only the agency of sensation, perception, feeling, and intel

lection, i.e., of cogitatio, thinking. Thus for Descartes, soul had to be

conceived as a res whose very essence or being was "thinking"; that

is, soul was a res cogitans. This meant that the connotation of "soul"

(anima, tyvyfi) came to be restricted to "mind," having been shorne of what previously (and not only in traditional Neoplatonism) belonged to its connotation, namely that of the principle of motion or change in the physical. The act or agency of soul was now entirely that of

"thinking."22 For Descartes there was a further evident implication of the

metaphysical dualism. Since soul is metaphysically distinct from and

independent of matter, the thinking of soul (which included sensing, perceiving) had of necessity to be "subjective," in the sense not only that the thinking belonged to the soul as thinking subject, but also that it arose in, and from, the soul itself?as opposed to being the

product of external efficacy, more particularly that of matter. This

was first of all evident from the conception of matter as completely without agency, thereby not being able to affect soul. Secondly, Descartes saw that this subjectivity of thinking was indeed entailed in the traditional Neoplatonic ontology of soul, in two respects. One

22 This meant a return to the fundamental conception of soul in Neo

platonism, that which soul essentially is, without its involvement with the

physical. The implications of this for the mind-body relationship will be ex amined below.



310 IVOR LECLERC

is that in this doctrine, since soul is "being," it is thereby "active" (in

act, ?v?pyeia), and in no respect "passive," i.e., "acted on" by any

thing without. The other is that soul, as "being," had to be cate

gorially understood as the subject, with the attributes, i.e., qualities,

quantities, relations, etc., conceived as "inhering in" that subject. Because "qualities" constitute the paradigm case of such "inherence"

(qualities giving "what" something is), the attributes in general had come to be spoken of as "qualifying" the subject. For Descartes, the

recognition of soul as metaphysically distinct and independent of the

physical or matter, entailed that these two implications of Neopla tonic ontology had all the more force. They constitute the ontological

ground of Cartesian "subjectivism."

Further, on this basis Descartes was able to deal with the issue of the interrelation of soul and matter, how it is to be philosophically explained in the crucial case of human beings in which there is evi

dently some kind of union of mind and body. It was clear that with the metaphysical dualism there could be no metaphysical necessity or

reason for any such interconnectedness. That is, the physical or mat

ter, as a res extensa, in no respect required any connection with soul; and soul, as ares cogitans, also in no respect required any connection

with matter. Therefore the reason for there being an interconnec

tion must lie wholly with the creative act of God. But even so, the unity is a peculiar one, in that it is not a substan

tial one, this being impossible by virtue of the metaphysical dualism. Since it cannot be supposed that God would violate ultimate ontologi cal and metaphysical principles, the philosophical problem is how, given the natures or essences respectively of matter and soul, that

interrelation is to be explained. For Descartes it was requisite first to recognize that as far as the

human body per se is concerned, it is analyzable into a multiplicity of

ultimately microscopic, differentially moving parts, and that all the

changes in the body are to be completely understood mechanistically, i.e., in terms of the locomotion of those parts according to the laws of

motion. Since the human body is a mechanism, there is no philo

sophical difficulty about completely comprehending it as such.

Difficulties, however, arise with respect to soul. For, corre

sponding to certain motions in the body, there arise "thoughts" in the soul. For example, if our body comes into close propinquity with

some other body which we call fire, the soul senses or feels heat, and

sometimes pain. Also, corresponding to certain motions in parts of




matter beyond our body, visual and other sensations occur in the

soul. These are among the most prominent instances of the intercon

nectedness with which we are concerned. That is to say, the difficul

ties center on "perception," and the philosophical analysis of percep

tion accordingly becomes crucial. Critics too regarded it as a test

case for Descartes' metaphysics, holding that, in terms of the meta

physical doctrine of the distinctness and separateness of soul and

body, perception is simply inexplicable; for perception would seem to entail that the soul is affected, i.e., "acted on," by body, which in Des

cartes' theory is impossible. Such a criticism, however, is made, implicitly at least, on the

basis of the medieval Aristotelian ontology and metaphysics, in ac

cordance with which physical beings are "active," "acting on" percipi ents which are, in that interrelationship, initially "passive," i.e.,

"acted on." Descartes on the contrary had completely rejected that

position, adopting instead the Neoplatonic ontology and a metaphys ics entailed by it. According to this, as we have seen, soul is wholly

"active," without any "passivity" or "being acted on." In terms of this

position, there can be no possibility of matter "actively affecting" soul. On the contrary, in Neoplatonism, from Plotinus and Augus tine onward, perception had been consistently explained entirely in

terms of the "act" of soul. That is, in perception, soul "acts" by "ac

tively taking account of" body. Descartes completely accepted this

analysis: for him the "act" of soul, as ares cogitans, is "thinking," and

perceiving is a mode of thinking, that in which the soul "takes account

of" the motion of body or matter.

Elaborating the perceptual interrelationship by including a sci

entific, anatomical account, Descartes held that motion in parts of

matter external to the human body is transmitted to those parts of

the body known as its sense organs, from which it is further transmit

ted to, and unified in, the pineal gland in the brain, which organ is the sensus communis. Thus far in this process, both external and inter

nal to the body, there is only matter in motion. Then the soul, en

tirely by its own acting, "takes account of the motion in the sensus

communis, "seeing" color, for example, or having some other sensa

tion.

The seeing of a color is having an "idea" in the soul. But for

Descartes such an "idea" is very different from an "idea" in anteced

ent philosophy, in which the "idea" in the mind is a form which is com mon with the form in the thing perceived. Since according to Des



312 IVOR LECLERC

cartes' dualistic metaphysics, there is no form such as a color or any

other qualitative feature in matter, it is impossible that the "idea" in the mind be a common form, and hence the "idea" in the mind has to

be wholly subjective to the perceiver. That is to say, it is metaphys ically impossible for such an "idea" to derive from matter, so it neces

sarily has to be subjective to the soul or mind. This means that it can arise only with the act of mind or soul. Thus Descartes is fully con

sistent with the Neoplatonic ontology, necessitating that soul be

wholly active, and not able to be "acted on." Descartes could there

fore justifiably feel satisfied that, on the basis of the Neoplatonic on

tology, he had an entirely consistent and coherent account ofthat cru

cial interrelationship between soul and body in the human being which is "perception." Once Descartes' Neoplatonic basis is recog

nized it is clear that it is erroneous to interpret him, as some have

done, as having been driven to occasionalism by his metaphysical du alism.23

Perception is, however, not the only interrelationship of soul and

body which Descartes has to account for and which is crucial to his

position. There is also the instance of soul evidently being able to cause motion in the human body. Descartes is able to do so only in

terms of the soul's acting. But the issue is how this acting, which is

"thinking," is able to produce a motion in matter.

Here also Descartes' Neoplatonic ontology provides the basis for

his solution. In the Neoplatonic doctrine, more particularly as main

tained by Augustine?which is the inheritance specially influential on Descartes?the "being" of the soul is, primarily, "thinking"; for Au

gustine this holds even for the "being" of God (in the second person). Now for Augustine, this "thinking" of God could not be what it was for Aristotle, a "thinking on thinking" (voriaeox; voyais), since God's

thinking "produces" or "creates" the world. Thus the thinking of God must include, besides intellection, also "willing," i.e., an "intend

ing to do." With this doctrine Descartes was in full agreement. As he wrote to Mersenne (27 May 1630): "In God, willing, understand

ing, and creating are all the same thing without one being prior to the other even conceptually."24 Therefore God creates matter, and mo

23 Cf. e.g., Norman Kemp Smith, Studies in the Cartesian Philosophy (London: Macmillan & Co.; New York: The Macmillan Company, 1902) and

New Studies in the Philosophy of Descartes (London: Macmillan & Co., 1952).

24 Kenny, p. 15; Adam & Tannery, 1: 152-53.




tion in matter, by "thinking"?which includes willing. Now Des

cartes held that God, in creating man as a res cogitans, had created

man in His own image, which meant that man's "thinking" includes

"willing." The role of "will" in Descartes' doctrine of knowledge, of

truth and error, is a profound one; that doctrine is that we attain

knowledge, i.e., truth in our thinking, only by properly "directing" our mind, which is to say by "will" intending our objects. The gen eral point is that "willing" is integral to the act of "thinking." This

point is crucial in Descartes' account of the relation of soul and body in which soul "moves" the body. This account is based upon recogniz

ing the analogy between man's thinking and God's thinking. As Des

cartes explained in a letter to Henry More (15 April 1649): "of course I do not think that any mode of action belongs univocally to both God and creatures, but I must confess that the only idea I can find in my

mind to represent the way in which God or an angel can move matter

is the one which shows me the way in which I am conscious I can move my own body by my thought."25 The "mode" of God's acting,

i.e., "thinking," is "creating," which in respect of matter includes

moving matter, as we have seen. But though the "mode" of acting,

i.e., "thinking," of a created soul cannot be that of "creating," i.e.,

bringing matter into being, nevertheless there is more involved in the

"thinking" of a created soul than only "knowing" matter as its object; because "thinking" includes "willing," by this the act of a created soul can be "directed toward" an object, a material body, with the "inten

tion" of a change in its motion. That is to say, while man's thinking, as a finite mode, cannot effect any change in the "nature" or "being" of matter, it can at least effect a change in the relations of one part of

matter to another, i.e., in the locomotion ofthat part of matter consti

tuting the human body, and more immediately that part which is the

pineal gland. This accords completely with the distinction between "act" and "motion" which we have seen above that Descartes insisted

upon.26 Almost all the motion of matter in the universe is caused by the thinking act of God, the res cogitans divina, but some of the mo

tion in those parts of matter constituting human bodies is caused by the thinking acts of the finite res cogitantes.

In terms of his Neoplatonic ontology, therefore, Descartes had a

consistent account of the soul-body relation, both in respect of per

25 Ibid., p. 252; Adam & Tannery, 5: 347.

26 See above, p. 305.



314 IVOR LECLERC

ception and also of the soul's moving of the body. It is readily com

prehensible that he should thus not have been at all perturbed by the

charges of his critics that the metaphysical dualism which he had em

braced entailed insuperable difficulties for the mind-body relation.

IV

Another set of philosophical issues which Descartes' metaphysi cal dualism forced him to rethink was that of "knowledge" and "truth." Here again Descartes did so upon the basis of his Neopla tonic ontology, drawing the implications necessitated with respect to these issues by his new metaphysics of the physical as this affected his metaphysics of the soul.

Descartes accepted from the tradition that "knowledge" con

notes "truth"; i.e., when we "know," this "knowledge" is the "truth"

about the object. This means, first, that the connotation of "knowl

edge" excludes any "might or might not be" with respect to truth?in

this, as Plato had insisted, "knowledge" stands in contrast to doxa,

"opinion." Secondly, connoted in "knowledge" is that it pertains to

"thinking" or "thought," and with respect to some "object." This

means that "knowledge" entails a reference of the thought to the ob

ject, this constituting a "correspondence" of the thought to that ob

ject. Thirdly, it is in the accuracy or conformity of that correspon

dence that "truth" consists.

Another most important acceptation by Descartes from the Neo

platonic tradition respecting knowledge is one going back to Plato, and Socrates, who had argued that to "know" that (say) a person or

an act is "just" or "virtuous," necessitated that one had the idea or

form of justice or virtue in one's mind. This means that the idea or

form was that in terms of which one is able to "know" that object, which is to say that the having of that idea or form in the mind is the "condition" of knowledge. For Plato, the ideas in the soul, those in terms of which it was able to have knowledge, were images or copies in the soul of the "Ideas themselves," which the soul gained by a

noesis (immediate intuition) of the Ideas themselves. In Neoplato nism, since everything derives from an ultimate One, the Ideas could

not have an ontologically ultimate and separate status as with Plato,

and thus became "ideas in the mind of God." For Augustine these

ideas were the archetypes or examplars for creation, and images of




these were created in human souls whereby those souls were "intelli

gences"; that is, those ideas in human souls were the principles of

knowledge, that in terms of which there is knowledge. For Des

cartes, in the Augustinian tradition, those ideas in terms of which there is knowledge were what he called the "innate ideas." These

were the ideas necessary to constitute this being a res cogitans, in its

essential respect as a "knowing" being. For Descartes the mathematician, among the most important of

the innate ideas were those which constituted the principles of mathe

matics, those fundamental ideas which are the principles of all mathe matical reasoning. The science of pure mathematics was constituted

by the explication, through the acting, i.e., "thinking," of the mind, of

the implications of those ultimate innate mathematical ideas. Pure mathematics is a "science," i.e., "knowledge," not simply by virtue of

the deductions being a logically correct elaboration of the implications entailed in those premises, since for Descartes, as we have noted

above, "knowledge" entails an "object" which is "known"; only

thereby is the "truth" of "knowledge" secured. This means that Des

cartes could not regard the outcome of the deductive elaboration of

the initial "innate ideas" as constituting "knowledge" unless there were an object to which this truly referred. This object, Descartes

maintained, is the physical or matter, which God had created a res

extensa, i.e., a res whose very essence is mathematical extension.

That is, pure mathematics is "knowledge," in the strict sense of the

word, of the essence of matter. This is what constitutes pure mathe

matics a "science" (in the etymological sense, i.e., "knowledge"), and

indeed, the science of the physical?which is to say that pure mathe

matics is physical science. Whence it is that Descartes stated, in the

concluding principle of part 2 of his Principles of Philosophy, "That I do not accept or desire any other principle in Physics than in Geome

try or abstract Mathematics."27 When one knows the "essence" of

the physical, "all the phenomena of nature can be explained by their

[pure mathematics] means, and a sure demonstration can be given of

them."28

Involved in the foregoing is another feature of the Neoplatonic doctrine of knowledge which was accepted by Descartes and devel

27 Descartes, Principles of Philosophy, pt. 2, princ. 64; Haldane &

Ross, 1: 269; Adam & Tannery, 8: 78. 28 Ibid.



316 IVOR LECLERC

oped as necessitated by the metaphysical dualism. This is that

"knowledge" is of the "essence" of an object, and specifically so of a

physical being as object. In traditional Neoplatonism this meant that

knowledge is of the form or soul of a physical being; form and not mat ter is the essence, the "what" the physical being "is," and only form is

knowable, since matter per se is completely unknowable. In Des

cartes' metaphysics, the physical being is matter, completely devoid of soul, and the essence of matter, that whereby it is what it is, is

mathematical extension. This, Descartes insists, can be perfectly known.

Another feature of the Neoplatonic doctrine accepted by Des cartes is the Platonic insistence that there can be knowledge only of

what is changeless. It is precisely the mathematical nature or es

sence of the physical, Descartes held, that is changeless, and thus

that it is this mathematical essence which is properly "known." There is change in the physical, but this change is not in the physical as matter, but is only a change of place, locomotion. But even this

change is "known" in the strict sense, for it is known in respect of what is changeless in it, namely the laws of motion; whatever bodies result from the locomotion of matter, and however they might move

relatively to each other, all this locomotive change is in accord with the laws of motion, which are perfectly known mathematically.

Descartes' conception of knowledge has another significant impli

cation, one which became of the greatest importance in subsequent

thought. This is one which Descartes saw to be fully consistent with his basic Neoplatonic position. Since knowledge, for example of the

physical, is grounded in the innate ideas, it follows that knowledge generally, and particularly of the physical, is subjective. This is a

point which did not receive emphasis in traditional Neoplatonism, re

specting which indeed it had been somewhat ambiguous. On the one

hand, in the Neoplatonic position, ideas are, categorially considered,

"qualifications" of the thinking subject, and as such inhering in the mind. But on the other hand, the qualitative ideas, as forms, were

regarded as common to the object and the mind. Now Descartes'

new metaphysical doctrine of the physical as matter necessitated, as

we have seen, the rejection of the qualitative ideas being forms com

mon with the physical. They could therefore not be other than en

tirely subjective. Therewith the ambiguity in traditional Neoplato nism is resolved, all ideas are wholly subjective.

But this brought to the fore an issue which had been raised in




Medieval philosophy, first by Arab thinkers and then in the Christian West. This issue, as it impinged on Descartes, was that the subjec

tive idea of the physical, which is an idea of the "essence" of the physi

cal, does not per se entail the "existence" of the physical. Could this

idea therefore constitute "knowledge" of the physical as its object? The difficulty is how the necessary correspondence condition of "truth" could obtain. Descartes' resolution of this issue was that the

actual existence of the physical is assured by God, the creator, not

only of matter as in its essence mathematically extended, but also of

mind with its innate ideas constituting it a "knowing" mind, and God, who is not a deceiver, would not create the mind with ideas, in terms of which to "know," if there existed no object to whose essence those ideas truly corresponded.

Descartes' dualistic metaphysics compelled him, however, to

make a basic distinction among "ideas." It was only the "innate

ideas"?prominent among which are the mathematical ideas whereby there is knowledge of the physical?which constituted that in terms of which there is knowledge. The qualitative ideas, contrary to tra

ditional Neoplatonism, have to be entirely rejected as giving truth and knowledge. The qualitative, particularly the sensible, ideas cannot possibly truly image the physical, since there is in matter

nothing whatever of a qualitative kind corresponding to those ideas.

They can at most "represent" some features of the motion in the

physical. Why then should we be created with ideas which are

strictly false respecting "what" the physical or matter is? The reason

lies in man, as a soul, being attached to a body, and having such ideas

is only to be useful for purposes of biological survival?for those pur

poses it is not necessary to know "what" things are in their essence.

As Descartes put it, "the perceptions of the senses do not teach us

what is really in things, but merely that whereby they are useful or

hurtful to man's composite nature."29

The conception of mathematics as fundamental in knowledge of the physical led Descartes to a further advance in his theory of knowl

edge, of how "knowledge" is to be understood. Not all knowledge is

respecting the physical; there is also that fundamental branch of phi losophy called "metaphysics" which, by the etymology of the word, seeks knowledge that extends beyond the physical, to all "which is."

29 Ibid., pt. 2, princ. 3 (heading); Haldane & Ross, 1: 255; Adam &

Tannery, 8: 41.



318 IVOR LECLERC

Descartes saw that metaphysics as "knowledge" could be consistently understood by extending the conception of "knowledge" of the physi cal as mathematical. This was to be achieved first by recognizing a

serious inadequacy in the commonly held conception of mathematics,

namely that it is essentially concerned with "order and measure

ment."30 Descartes had attained an insight of great importance with

regard to "what is universally meant by the term," i.e., what is the

most general character of mathematics.31 This general character,

Descartes maintained, is not that of "order and measurement" but

that of "relationships and proportions."32 With the recognition of

"relationships and proportions" as the general or generic concern of

mathematics, it was easy to see "order and measurement" as being a

species of that general character. Descartes was thus led to the con

ception of a mathesis universalis, "universal mathematics," that is to

say, of mathematics in its most general or universal respect, in which

there is no specific restriction, such as to "measurement."33 With

this fully general conception of the nature or essence of mathematics, Descartes could see that, while some branches have a particular con

cern, e.g., with measurement, there could be others which would not

have any such particular restriction, and which would thus be more

general. Now philosophy, and especially "first philosophy" or "metaphys

ics," is concerned with the most general?not only with respect to

the physical, but to all "which is." That is, metaphysics is thinking which is concerned with the most general, and "thinking" in this re

spect, as had long been recognized, is "ratiocination," i.e., it is think

ing proceeding in terms of ratio, "proportion." Thus metaphysics is

the manifestation par excellence of mathesis univer salis. This is to

say, metaphysical thinking is essentially mathematical; it is the high est instance of mathematical thinking (in that general sense of "mathe

matics"), because it is thinking concerned with full generality. Fur

ther, since thinking which is "knowledge," and thereby "true," must

have an "object," the object of this metaphysical or general thinking must be the essence of all "that is"?i.e., ofthat which is created. Now

30 Descartes, Rules for the Direction of the Mind; Haldane & Ross, 1:

13; Adam & Tannery, 10: 377. 31 Ibid. 32 Ibid. 33 Ibid.




Descartes had maintained that the essence of the physical is "exten

sion," which is to say that its essence is mathematical; and that the

essence of the other created res is "thinking." It has now emerged that "thinking" also is "mathematical" (in the general sense). Thus

creation consists of two kinds of "being" or res: one res whose essence

is mathematical extension, and the other res whose essence is mathe

matical thinking. This metaphysical conception or theory of Des

cartes, of there being two kinds of "being" the essence of each of which is "mathematical," must be "true," since that conception or the

ory corresponds to what is indeed the essence of the respective res.

Moreover, that conception itself is completely general, it itself being in essence "mathematical." Thus Descartes' metaphysical theory, as

"true," constitutes genuine "knowledge," in the fullest sense of the

word.

It is to be noted that this doctrine of Descartes is completely Neoplatonic. It is, however, not original with him; the essentials of this doctrine, that the physical is a mathematical structure, and of

mathematical thinking as being the paradigm of genuine knowledge,

having been advanced by that most important reviver of Neoplato

nism in the fifteenth century, Nicolaus Cusanus, from whom it came to

be shared by many of Descartes' contemporaries, notably Galileo.34

The fundamental point in this which I want to stress is that real

knowledge is achieved by the "explication" of the ultimate "ideas,"

which are innate or original in the soul in its creation. Descartes,

however, was the first to achieve a full elaboration of this position into a comprehensive, detailed, and consistent system, philosophical and

scientific.

One important development of this basic Neoplatonic position by Descartes?one which he made much more consistently than did Cu

sanus?was respecting philosophical method. Descartes insisted

that the explication of the innate ideas, which essentially constitutes the highest kind of thinking, is clearly exemplified in mathematics, i.e., the carefully controlled procedure of deductive inference from ul

timate premises, which were the given "innate ideas." What was en

tailed, Descartes maintained, was that any "thinking" which led to

genuine "knowledge" had to proceed by this deductive method. Thus

the primary methodological problem was correctly to discern those

34 See my The Nature of Physical Existence, chap. 5, esp. p. 82.



320 IVOR LECLERC

"ideas" which are the genuine premises. The answer to this prob

lem, for Descartes, was that of Christian Neoplatonism, namely that

God created the soul with the ability or capacity to "intuit," i.e.,

directly apprehend, those "ideas." This, for Descartes, was the nat

ural capacity of the soul, i.e., that which constituted its "nature" by God's creation, which Descartes often referred to as the "natural light of reason."

Because, however, human beings are apt to be misled respecting the ideas constituting the real ultimate premises (e.g., by being di verted to paying attention instead to the sensible ideas), it was conve

nient, in expounding his philosophy, to adopt, as a heuristic device,

the method of hyperbolical doubt. It is to be observed, however, that this method per se is not self-justifying as leading to the truth: there is no ground in "doubting" to conclude that one must thereby be led to any one or more instances of "truth" or "indubitibility." The

justification of the method lies in Descartes' Neoplatonic presupposi tion that there are in the soul certain ultimate ideas derived from

God, and that the soul has the natural capacity to "intuit" them. Fur

ther, it is to be noted that this Neoplatonic presupposition is also the

ground for Descartes' criterion of the correctness of the intuition,

namely that of "clarity and distinctness." That is to say, subjective

"clarity and distinctness" cannot per se constitute justification for the "truth" of the perception ("truth" entailing correspondence); it is

based on the above Neoplatonic presupposition.

V

In conclusion I should like to enter into a consideration of the sta

tus in general of Descartes' Neoplatonic ontology in his system of

thought. Thus far I have sought to show that his ontology is quite basic to Descartes' philosophy, in that it is fundamentally determina tive of his position, not only in metaphysics in general, but also of his version of the new metaphysics of the physical as matter, and of his

metaphysics of the soul, as well as of his philosophical psychology, and of his philosophical anthropology, and further of his epistemology and his methodology.

The issue I wish now to raise is that of the justification of that

Neoplatonic ontology. What is Descartes' justification of it? Does he give a justification for it? It does not seem to me that Descartes




gives any justification for it, other than to show that in terms of it he has a coherent and consistent philosophical system, one in terms of

which he is able consistently to understand and interpret the new sci

entific developments of the seventeenth century?his success in

achieving this is not to the point here. It could be said, however, that Descartes does have a justifica

tion for it in his doctrine of "innate ideas," more particularly in the innate ideas of "God," "being," "essence," "existence," "causality," etc.?those which were the premises of his metaphysical argument

respecting the existence of God in his Meditations. That is to say, those particular ideas are systematically interrelated?as opposed to

being atomistically independent?whereby they entail that Neopla tonic ontology. For example, the fundamental ontological idea,

"being," is for Descartes necessarily systematically coordinated with

the idea of "God." What that "idea of God" connotes he makes quite

explicit: e.g., in Meditation 5 it is "the idea of a supremely perfect being,"35 i.e., "a Supreme Being, to whose essence alone existence

pertains";36 and in the Principles of Philosophy he states that "when we reflect on the idea of Him which is implanted in us, we perceive that He is eternal, omniscient, omnipotent, the source of all goodness and truth, creator of all things. . . ,"37 From the ontological per

spective, this clearly entails the Neoplatonic ontology. In other

words, when we explicate what is implicit respecting "being" in,

chiefly, the idea of "God," we will arrive at the Neoplatonic ontology,

i.e., conception of "being." Further, the conception of this ontology as "given" to the soul by God is entirely coherent with that ontology itself. What is meant by "coherence" here is that there is no arbi

trariness about the givenness of that ontology, as being entailed in

the innate idea of "God": for the Neoplatonic ontology itself requires its being thus given, since the essential position of the Neoplatonic ontology is that "being" and "ideas" derive from God?in this dif

fering fundamentally from Plato?all the thus derivative or "innate"

ideas, including that of this ontology itself, being given to souls as the ultimate conditions of knowledge. This coherence could be claimed

35 Descartes, Meditations 5; Haldane & Ross, 1: 180; Adam & Tan

nery, 7: 65. 36

Ibid.; Haldane & Ross, 1: 183; Adam & Tannery, 7: 69. 37


Ross, 1: 228; Adam & Tannery, 8: 13-14.



322 IVOR LECLERC

as justifying the Neoplatonic ontology, and it might well have been taken as such by Descartes himself.

But the question is whether it does indeed constitute an ade

quate justification. A significant aspect of this "coherence" is that Descartes' deductive philosophical method, whereby indeed that co herence is displayed, is itself, as we have seen in the preceding sec

tion, required by Descartes' Neoplatonic ontology. Now there is a

significant difficulty in this. From Descartes' point of view as a

thinker, thinking deductively, his thinking has to proceed from cer tain premises?the innate ideas. These premises are "given," and as

such are assumed by Descartes. The question can be, and needs to

be, raised as to the justification of that assumption. Is that assump tion justified by the method itself? Certainly this method presup

poses that assumption respecting the "givenness" of the innate ideas; but that his method requires that presupposition cannot itself consti tute a justification for that presupposition, since that presupposition itself is open to question?that is, that presupposition itself requires to be shown to be true. If Descartes were to argue that the truth of

that presupposition, viz., of his ultimate premises, is assured by the

Neoplatonic ontology, or by the doctrine of God as the sole source of

everything, including "all goodness and truth," his argument would

be circular, for that very doctrine is a presupposition, and cannot val

idly be adduced in support of its truth. What emerges from this is that Descartes is compelled by his

method to assume certain doctrines as true. But there is no way for

him to guarantee, or to establish indubitably, their truth. In fact, Descartes' belief in the truth of the presuppositions and premises of his method, is not grounded in the method; it is grounded in his Chris tian Neoplatonic heritage. In other words, that ground is ultimately religious, and not philosophical.

Finally, a consideration needs to be made here of the philo

sophical status of this basic "assumption" of Descartes' philosophical thinking and method. Religious conviction can be no guarantee of

philosophical "truth." What, then, is its status? I would submit

that, philosophically considered, its status is that of a logical "hypoth esis." This means that Descartes, contrary to his conception of philo

sophical method as purely deductive, in fact proceeded by the "hy pothetico-deductive" method. Descartes' Neoplatonic ontology is his

fundamental philosophical hypothesis. In this Descartes' philo sophical scheme and method are not different from any other; every




philosophical scheme is necessarily dependent upon some basic hy

pothesis, for, as Whitehead has put it, "there are no precisely stated

axiomatic certainties from which to start."38

Emory University.

38 A. N. Whitehead, Process and Reality (London: Cambridge Uni

versity Press; New York: The Macmillan Company, 1929), pt. 1, chap. 1, sec. 5.



the ontology of descartes

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