ARISTOTLE, THOMAS, AND DESCARTES’ MEDITATIONS
In his Discourse on the Method of 1637, Descartes ridicules the Aristotelian/Thomist maxim, “there is nothing in the intellect that is not previously in the senses.” Descartes intended to expose the logical absurdities that follow from giving sense perception priority in the rational soul’s operation of understanding:
The reason for this is that they never raise their minds above things which can be perceived by the senses: they are so used to thinking of things only by imagining them (a way of thinking specially suited to material things) that whatever is unimaginable seems to them unintelligible. This is sufficiently obvious from the fact that even the scholastic philosophers take it as a maxim there is nothing in the intellect which has not previously been in the senses [Ce qui est assez manifeste de ce que mesme les Philosophes tienent pour maxime, dans les Escholes, qu’il n’y a rien dans l’entendement qui n’ait premierement este dan le sens]; yet it is certain that the ideas of God and the soul have never been in the senses.
According to Descartes, the soul knows neither itself, nor God through sense images because it is not the substantial form of the human body— certainly not in the Aristotelian/Scholastic sense of the soul as the form of the body. Descartes’ methodological doubt furnishes him with the requisite conditions for dispensing with the Aristotelian theory of knowledge that asserts the primacy of sense images in matters of rational intelligibility. If the soul knows nothing through sense-images, the only available avenue for indubitable knowledge of the existence of God and the soul is via “separation of the mind from the senses” [abducere mentem a sensibus] to discover the innate knowledge of the existence of God and the separabilty of the mind from the body.
Like his Regulae, Descartes’ Meditations become intelligible when read as a conversation with Aristotle and his Scholastic descendents, such as Scotus, Ockham, and above all, Aquinas. When Descartes broaches the question of the nature of the soul in his prefatory letter to the Sorbonne in the Meditations, he has nothing other than the opening of Aristotle’s De anima in mind, writing, “As regards the soul, many people have considered that it is not easy to discover [non facile investigari] its nature…” Aristotle’s procedure for inquiring into the soul in De anima begins with what is perceptible and moves to the underlying principle or mechanism that makes objects intelligible to the mind: “…in the order of investigation the question of what an agent does [movement] precedes the question, what enables it [i.e., the soul] to do what it does.”
The completely separable and independent essence of the mind, Descartes argues, involves two modifications of the Aristotelian/Thomistic account of man as a rational animal. First, Descartes rejects the Aristotelian/Thomistic conception of the rational soul, whose mode of understanding is “through an intelligible species,” or “turning toward phantasms” [se ad phantasmata)]. Second, Descartes rejects the Aristotelian/Thomistic conception of the substantial union of rational soul and body by denying not only the verity of the knowledge of species gained through the senses, but also entertaining the possible non-existence of all bodies. The two latter steps are necessary for Descartes to affirm the superior epistemological status of “the thinking thing” [res cogitans] over extended things [res extensia]. Only the “thinking thing” distinguishes the true from the false and uncovers the ontology of the soul in an intuitive, self-reflexive act (Descartes’ cogito). Only when the mind is free of sensory interference can it apprehend the innately contained ideas of the existence of God and the separability of the mind from the body.
On the contrary, Aristotle and Thomas assert that the soul is the mover of the body. The soul/mind, according to Descartes, is not responsible for the movement of the body; rather, the mind’s only operation is thinking. That is the reason why, after rejecting the Aristotelian/Thomistic account of the soul as the mover of the body, Descartes’ chief problem in the Meditations is demonstrating how the soul or mind is connected to the body. The circulatory system, Descartes argues, is responsible for the movements of the body; the mind is only aware of the body in respect to the sensation of pain, or other corporeal necessities, such as the body’s sensation of hunger or thirst. Aside from the rational mind’s embodiment in the human animal, the mind, so to speak, owes nothing to the body, and vice-versa. Hence, the mind, Descartes, argues, has no need of the bodily senses to grasp the essential nature of objects. The senses do not think, only the mind does. Thus, the mind’s innate ideas of concepts such as the existence of God, the ego, or the essence of wax need no corresponding tie to objects in the material world (which, for Descartes, may not even exist). Accordingly, the ego’s act of existence cannot be said to depend on the beginning or end of the body to which it is somehow attached. The very nature of the Cartesian mind is found through foundational ideas that have no exact correlative in the material world, such as the existence of God and the separability of the mind from the body.
Like Descartes, Thomas Aquinas’ obligation to abide by the Catholic Church’s dogma of the soul’s immortality required demonstrating that the soul, as the form of the human body, is separable from the body. Reckoning Christian doctrine with Aristotelian philosophy necessitated Thomas’ modification to Aristotle’s account of the soul in De anima. Because the question of the immortality of the intellective soul is left open in the Aristotelian account, Thomas argues for the substantiality of the rational soul per se. On the other hand, Descartes’ theory of cognition presupposes the body and senses as being obstacles to the mind’s knowledge of the truth. The mind can continue all of its cognitive operations independent of any contribution from the body’s sense organs because the objects of cognition do not come without, but from within the mind (“only the mind inspects” [inspectum mentus; or alternately, sed solius mentis inspectio]). Descartes seeks to demonstrate that the mind alone understands, and that only knowledge contained innately in the mind is indubitable. Confirmation of this fact is stated explicitly by Descartes: “…it is certain that I am really distinct from my body, and can exist without it.” The “soul as the form of the body” [anima corporis forma] of Aristotle and his Scholastics descendents is eradicated by the first act of Cartesian doubt— calling the reliability of the senses into question. The only operation of the Cartesian mind, thinking, does not require a substantial union with a particular kind of body, or a body at all. In spite of his claim that the soul forms a substantial union with the body, Descartes broke the substantial union.
DESCARTES’ ANTI-ARISTOTLEIANISM IN THE DEDICATORY LETTER TO THE SORBONNE
To gain the commendation of the Sorbonne for his Meditations, Descartes required a subtle method of aligning his ostensibly anti-Aristotelian conception of God and the human soul with the views upheld by the conservative Aristotelians of the Sorbonne faculty:
…I have noticed both that you and all other theologians assert that the existence of God is capable of proof by natural reason, and also that the inference from Holy Scripture is that the knowledge [cognitional] of God is easier to acquire than the knowledge we have of many created things…”
Descartes presents his conception of man’s knowledge of God’s existence and the immortality of the soul in an attempt to persuade the theologians that his metaphysics does not diverge from the main topics of prior systems, but serves to reckon together and codify all “arguments that have been put forward on these issues by the great men.” Descartes praises his predecessor’s arguments as having “the force of demonstrations.” But Descartes’ claim of upholding orthodoxy in his dedicatory letter should be considered further alongside the claim he makes in his Letter to Voetius. In his letter, Descartes argues that Thomas’ proofs for the existence of God have all been found to contain invalid conclusions, and are therefore inconclusive, if not faulty proofs. If anyone is guilty of Atheism, Descartes declares, Thomas is the more culpable, pointing out that Thomas’ proofs for the existence of God have been disproven, whereas his never can be.
In his prefatory letter to the Sorbonne, Descartes strategically combines established doctrines of the Church with the traditional Scholastic endeavor to generate proofs for the existence of God and the immortality of the soul. However, in his Meditations, he ingeniously modifies the purpose of speculative philosophy and natural theology to support the practical ends of science. It is noteworthy that the Sorbonne letter only contains one passing mention of science, when in fact, the purpose of the Meditations is an attempt to establish a firm foundation upon which to raise the sciences.
Because Descartes’ physics derives entirely from his metaphysics, he is able to sidestep the fact that his speculative metaphysics overturns the speculative physics of Aristotle. The two main points Descartes addresses in his dedicatory epistle to the Meditations are proving the existence of God and demonstrating the immortality of the soul. He frames the latter problems in terms of the historical search for definitive philosophic proofs. If the existence of God and the immortality of the soul are provable, then atheism and religious skepticism can be combated with the assurance of victory. Descartes’ project of providing a firm metaphysical foundation for the sciences is carried out according to the established template of the Scholastic philosophers, and consists of a synthesis of speculative metaphysics and Christian theology. But by taking a reductionist approach to the history of philosophy and, indeed, to the act of philosophizing itself, Descartes is able to critique and sweep aside the writings of his Scholastic predecessors with his claims of logical soundness and indubitability for his proofs in the Meditations.
Descartes’ conception of one universal science, whose “roots are metaphysics, the trunk is physics, and the branches emerging from the trunk are all the other sciences…,” requires that the method used for augmenting the sciences be single, in order for truth to be demonstrated in a systematic order. The indemonstrability of Aristotle’s first principles for reasoning is transformed, under the auspices of the Cartesian method, into the test of indubitability for arriving at epistemological certainty in derived propositions. Descartes’ synthesis of speculative metaphysics and Christian theology differs from the Scholastic’s metaphysics and theology in the respect that the aim of discovering a method to derive indubitable metaphysical principles to augment the sciences was never present for Scholastic philosophers. For Descartes, the theological imperative to demonstrate the existence of God and the immortality of the soul developed out of a rationale opposed to the Aristotelian/Scholastic concept of theoria (the contemplation of truth) as the utmost goal of philosophizing.
The philosophers of Antiquity commonly divided human activity into two spheres derived from two modes of understanding: the active life, derived from “opinion,” or subjective experience, and the contemplative life, derived from the mind’s rational faculty to apprehend objective concepts and objects. For Aristotle, life begins in the sphere of practical activity and ends in the act of philosophic contemplation of the unmoved Divine. For Aristotle as well as Thomas, metaphysics is the most logical and objective of the sciences, and crowns the investigation of being as being. The other sciences, which take practical activity as their end, are naturally inferior to metaphysics, and form a basis for the rational investigation of the Diving.
Descartes accepts the premise that metaphysics is superior to all the other sciences. Yet metaphysics is, as he calls it, the roots of his system, and not the speculative crown that metaphysics represents to Aristotle and Thomas. Philosophy, for Descartes, need no longer be speculative; first principles need no longer be sought for their own sake. The tradition of speculative philosophy is no longer viable in the scope of a theoretical philosophy with practical ends. For Descartes, the end of philosophy is not the science of the search for first principle— or, the speculative exploration of Divine attributes. Rather, the practical end of philosophy is the project of applying indubitable principles to formulate and discover practical aids to remedy the ills of human existence. In his Discourse on the Method, Descartes states that raising the sciences on a rational and indubitable foundation will recapture for man the position he once owned in the Garden of Eden— “master and proprietor of nature.”
By replacing speculative philosophy with practical philosophy, Descartes rejects not only the contemplation of truth as the goal of philosophic activity, but takes religious and philosophical skepticism as his chief enemy from the beginning, rather than the thought of Aristotle and the Scholastics. Descartes held that the proofs found in the writings of the Schoolmen for the existence of God and the immortality of the soul failed to attain their objective, and amounted in the end to a mere demonstrations that the truths of faith and the truths of reason do not lie in opposition to each other. Such demonstrations, Descartes held, were insufficient to combat the tendency in the 17th century toward atheism and religious skepticism. The only sufficient criterion for the test of indubitable knowledge is the mind’s perception of a truth that impresses itself with such force and vivacity that the mind cannot help but assent to the validity of the proposition (e.g., that God exists). According to Descartes, such truths are what the mind perceives “clearly and distinctly.” All other families of propositions fall within the realm of Aristotle’s indemonstrable first principles and Thomas’ secondary causes.
In his Dedicatory Letter to the Sorbonne, Descartes presents his Meditations to the Dean and Doctors as a work of Christian apologetics. However, he is not forthcoming about his incendiary goal of demolishing the whole of the Aristotelian metaphysics, physics, and psychology. Descartes’ principle of “methodological doubt” [rationem dubitandi] functions as a tool for overturning what Aristotle and his Medieval Scholastic followers took for granted — the reliability of the rational soul’s knowledge of the material world acquired through the senses. In the 17th century, Aristotelianism and Thomism predominated among the faculty members of the Sorbonne. According to the prevailing Aristotelian doctrine in the Schools, the first principle of man’s knowledge is the sensible apprehension of objects in the material world. The sensible apprehension of objects depends upon the sensible object received by the agent intellect via the phantasm, or image. Without the sensible object, neither the agent nor the possible intellect could be, in a sense, activated. Without the particulars of sense knowledge, the intellect’s abstraction from particular objects to grasp the intelligible species could never take place. Cognition as such would be impossible for Aristotle’s man. Except as a peripheral question, neither Aristotle nor any Scholastic philosopher prior to Descartes ever took seriously the question of the reliability of sense perception as a conduit of genuine knowledge.
Descartes begins his Meditations by inquiring into whether the rational mind is capable of a type of purely rational mental activity comparable to Aristotle’s conception of contemplation [theoria]. To do so, however, Descartes reverses Aristotle’s procedure for inquiring into the nature of the soul. To see how this is done, it is necessary to point out that Aristotle does not begin his inquiry into the nature of the soul with cognition, since thought itself is neither perceptible, nor is it an intelligible species that takes itself as its own object. In other words, Aristotle’s account of the rational soul does not begin with a demonstration of rationality. Philosophy begins, according to Aristotle, by setting out principles that, for the rational mind requiring material particulars to abstract universals from, are indemonstrable principles. The famous principle of non-contradiction is one example of Aristotle’s indemonstrable “first principles.”
In the Sixth Meditation, Cartesian philosophy’s crowing project of the “mastery of nature” ends up where Aristotle’s philosophic project (in De anima) begins. Descartes’ last chapter in the Meditations gives an account of the movement and activity of the animal possessing a rational mind. The purpose of his account is twofold: first, to developing cures for the infirmities of the body to which the mind is attached as “a pilot in his ship”; second, Descartes hoped to raise man through the development of the sciences to the status of the “master and proprietor of nature.” Descartes’ theory of the separability of the mind and body stands in opposition to his theory of the substantial union of the mind and body, which, he writes, is not merely the relation of mover to the thing moved, but a relation where the mind and body are “very closely joined” so as to “form a unit.” Translated into the Aristotelian vocabulary, the Cartesian theory of cognition states that the universal or essential nature of an object is known prior to, and more easily, than the particular material object in the world grasped through the corporeal senses. The first principle of knowledge, according to Descartes, is not objects in the material world or concepts that abide the principle of non-contradiction. Rather, the first principles of knowledge are contained in the innate ideas that the mind has of all objects, including God and the self, independent of all sensory perceptions. These principles, Descartes holds, are indubitable, and therefore more logically consistent than Aristotle’s indemonstrable first principles that seem to assert the priority of the objects of knowledge over the knower.
In the Dedicatory Letter of the Meditations, Descartes’ argument from the Bible regarding the mind’s intuitive or innate knowledge of the existence of God implicitly corroborates the argument given in the Meditations for why the soul’s nature is easily discovered. The mind’s innate idea of God is demonstrable from the essence of the mind itself, which, as an incorporeal thinking substance, is entirely distinct and separable in its operations from the body and its senses. Descartes’ celebrated phrase, sed solius mentis inspectio, or “the mind alone inspects,” reverses the Aristotelian order of operation by which the rational soul understands external objects. To meditate, according to Descartes, is to detach the mind from the senses, because the sensory-dependent body is an obstacle to knowing the truth.
Descartes sought to align his proofs for the existence of God and the immortality of the soul with the long-accepted proofs of his Scholastic predecessors. In his dedication, Descartes calls his addressee’s attention to the fact that his project of proving the existence of God and the immortality of the soul corresponds to the traditional Scholastic enterprise. Further, Descartes cites the eighth session of the Lateran Council held under Pope Leo X (Apostolici Regiminis, 1513) to legitimize his philosophical investigation into the existence of God and the human rational soul. By adopting Leo X’s mandate for Christian philosophers to refute the arguments of irreligious philosophers who hold “that the soul dies along with the body,” Descartes hoped to gain the commendation of the Sorbonne’s Aristotelian/Thomist faculty members.
Be that as it may, Descartes’ mission as a philosophical apologist for the truth of Christian doctrine involved more than simply upholding the tenets of the Faith with rational arguments, as there was nothing innovative in doing so. The sense that Aristotelian philosophy was a stagnant body of knowledge prompted Descartes to look afresh at the foundations of philosophy. In making Thomas Aquinas its representative theologian, the Church had implicitly “Christianized” the thought of Thomas’ master, Aristotle. Descartes considered the alliance of Christian and pagan philosophy to be hazardous to the central doctrines of Christianity. Making Christian philosophy dependent in crucial ways on the philosophic principles and reasoning of a pagan philosopher left the Faith vulnerable to the attacks of atheist and religious skeptics. In his Meditations, Descartes hoped to free Christian philosophy from the bonds of Aristotelian philosophy by abrogating its epistemic foundations. By framing the traditional questions of philosophy in a Christian context, Descartes hoped to secure an indubitable foundation for the two main tenets of Christian philosophy: that God exists and that the soul is immortal. Descartes demand for an undiluted foundation for religion set the stage for a new philosophy that depended on neither sense perception, nor the dogmas of Aristotelian Scholasticism.
DESCARTES’ CONCEPTION OF MIND VERSUS THE ARISTOTELIAN
CONCEPTION OF THE SOUL
The publication of Gilbert Ryle’s The Concept of Mind (1949) originated the analytic approach to Cartesian thought. Unfortunately, analytic commentators of Descartes’ writings take little account of the historical background of the 17th century in formulating their interpretations; nor do they give little more than a sign of acquaintance or interest in the writings of Thomas or the Scholastic philosophers. Such interpretations have little to offer the historian of philosophy. Commentary that ignores the anti-Aristotelian/Thomist position of the Meditations arrives at conclusions that are conceptually dazzling, but ultimately refer only back to themselves, rather than the historical sources of Descartes’ writings. The validity of Descartes’ arguments have been borne out or disproven according to the whims of History’s mistress, lady Fortune. The internal logical consistency or inconsistency of Descartes’ Meditations does not illuminate the main themes or reason for his writing the book. No does the analytic approach consider for whom Descartes wrote the book. An historian of philosophy might fruitfully beg Aristotle’s question, “were the Meditations persuasive to Descartes contemporaries?” Descartes aimed to construct a metaphysics that did not depend on the Aristotelian account of material reality or the speculative metaphysics and dogmas of the Schools. To do so, he had to contend with the prevailing thought of the Schools, which happened to be principally Aristotelian/Thomist. Reducing the status of Cartesian metaphysics to a sterile series of mental acts of consciousness misses Descartes’ dual point that a metaphysical foundation must first be in place in order to generate indubitable scientific principles. Only after a system of metaphysics is in place can the programme originating in the writings of Francis Bacon, viz., making man “the master and proprietor of nature,” be realized.
In the Sixth Meditation, Descartes’ demonstration of the separabilty of the mind/soul from the body consists precisely in the clarity and distinctness of the perception of what belongs to the essence of thinking things [res cogitans]. Regarding extended things [res extensia], the same clarity of perception does not apply. Extended things are perceived only distinctly, which is to say, not essentially. The meditator’s essence consists in “absolutely nothing else” than that he is “a thinking thing…” Descartes cancels Aristotle’s formulation of the soul as the form of the body, which assumes the givenness of the objects of perception, in his demonstration of the incorporeal existence of mind/soul as being more clearly and distinctly known than the existence of objects extended in space and perceived by the corporeal senses. In Aristotelian teleological thought, the difficulty in giving an account of the soul lies with the process and methods of investigation: beginning with sensible perception of particulars, the faculty or ordering principle (soul) is abstracted from observing the respective activities of sentient beings. Conversely, in order to determine the existence and nature of the soul, the Cartesian method bypasses the information gathered through the senses and inquires instead into the origin of the mind’s ideas, which are divided into three types: adventitious, composite, and innate.
Turning to the Aristotelian conception of the soul, in De anima II, Aristotle formulates his doctrine of cognition through abstraction as, “the soul never thinks without an image.” In other words, the intellect, whether human or animal, is activated by sense images, and neither cognizes nor wills prior to the mind’s reception of sense data. Like the sensitive soul of animals, Aristotle’s third type of soul, the rational soul, is dependent on the image, or phantasm, gathered by means of the senses. The rational soul’s faculty for abstract cognition is activated by sense images and impressions. Considering the operations of the rational soul (movement, sense perception, abstraction), the cognizing activity of the potential intellect called abstraction cannot take place without the object of thought having first passed through the agent intellect, whose activity is the passive reception of sense data. However, for its abstract cognitive operations, the rational soul is exempt from further dependence on sense impressions. Insofar as the rational soul neither grows nor senses as such, its operation of abstraction from sense images does not dependent on further contribution from the body’s sense organs.
Aristotle’s proof for the soul begins with evidence derived from motion in the order of corporeal being, such as the fact that animals possess the power of self-movement and growth. The empirical fact of motion is requisite to all of Aristotle’s claims about the soul. If nothing were in motion, as in the static world of Parmenides, the senses would have no purpose for existing, as there would be nothing to sense. Thus Aristotle states that the sense’s primary reason for existing is to convey images of objects in motion to the passive intellect. Abstraction of images from the passive intellect are understood by the active intellect, the faculty of the mind responsible for rational thought. On the basis of movement, Aristotle causally deduces the formal principle from the material principle. For example, creatures that grow and reproduce must themselves be animated by some kind of mover, which Aristotle tells us is the soul. Moving creatures are animated by two of Aristotle’s three types of soul: the nutritive and sensitive. The existence of the soul proven from the evidence of motion in the sensible world is a naturalized account of the soul. Because objects are intelligible, sense perception has, for Aristotle, the nature and value of a principle of knowledge. Consequently, to gain any certain knowledge of what the essential nature and properties of the soul are, the operations of the senses must be considered.
In response to Aristotle and his Scholastic followers, Descartes’ treatment of the soul in the Meditations begins with the question of what, if anything, can be known with any epistemological certainty, and proceeds by applying the methodological doubt to everything dubitable by the light of valid reasoning (propter validas & meditates rationes). The possibility of material objects serving as the source of the first principle of metaphysical knowledge is rejected, and the project of discovering a source of indubitable knowledge on which to found the sciences is directed toward the discovery of the innate cognitive perceptions of God and the ego. The methodological doubt and the hypothesis of the malin génie, detailed in the first two Meditations, furnishes Descartes with the necessary conditions for abrogating any theory of knowledge that asserts the primacy of sense images in matters of rational intelligibility. Descartes’ argument against the soul as the form of the body reverses the Aristotelian/Scholastic axiomatic sense of the soul as the form of the body [anima corporis forma]. According to Descartes, information or data derived from sense-images is subject to the methodological doubt precisely because the soul is understood to be something other than the substantial form of the body. Hence, any dependence on the senses to confirm the truth or falsity of ideas must be forsworn at the outset if the criterion for telling the true from the erroneous has premises more robust than a posteriori. If the soul cannot know anything through sense-images, the only available avenue for indubitable knowledge, particularly indubitable knowledge of the existence of God and the immortality of the soul, is through “separating the mind from the senses.”
In the Second Meditation, Descartes’ phrase, “the mind alone inspects” represents a kind of pastiche of Aristotle’s definition of the soul in De anima II, where the soul defined as “the form of a natural body having life potentially within it” (or capable of living). Aristotle’s formulation precludes the question of “whether the soul and body are one”— which question, he concludes, is as meaningless as inquiring “whether the wax and the shape given to it by the stamp are one.” The view of the wax as inseparable from the stamp given to it assumes, by analogy, that that which organizes (soul), and that which is organized (body) cannot be distinguished. In two ways the Aristotelian rational soul is inseparable from the body: first, because the soul is the form of the body; and second, because the soul depends on the corporeal sense faculties in order to satisfy the goal, or telos toward which its operations of growth, nutrition and reasoning tend.
When Descartes exposes a quantity of beeswax to fire, the intention is to distinguish two separate modes of perception, sensuous and cognitive, and thus argue for why the demonstration of the distinction between the soul/mind and the body is necessary. The perceptible “stamp” of the beeswax remains even once its recognizable qualities have been altered by exposure to the fire; viz., its taste, fragrance, odor, figure, sound, &c., are not done away with because the essence of the beeswax is not contained in any of its innumerable accidental properties. Descartes states, “the perception I have of it [wax, or any material object] is a case not of vision or touch or imagination — nor has it ever been, despite previous appearances — but of purely mental scrutiny [sed solius mentis inspectio]…” Objects, such as the beeswax, can be “sensed”; but the corporeal senses do not “think.” Hence, the ideas of objects perceived by the mind cannot bear any relation to the properties of objects perceived by the corporeal senses: “perception derives not from their [objects] being touched or seen but from their being understood.”
Moving from the idea that the mind alone inspects the essence of objects, Descartes is in a position to inquire into the essence of the rational soul. If the mind alone knows objects through their essences, the mind can presumably inspect itself, or perceive its own essential nature. “I know plainly that I can achieve an easier and more evident perception of my own mind than of anything else,” Descartes concludes. He then overturns the common sense opinion that “the bodies which we touch and see” are perceived aright by the senses. The mind or soul grasps the essential nature of material objects without the aid of the corporeal senses. Thus, a question considered by Aristotle to have a self-evident answer, namely, whether the soul and body are joined in an interdependent relation, is considered in Descartes’ inquiry into perception to have been given a less than satisfactory answer.
In the case of man, according to Aristotle, rationality is not a superficial addition to animality, but rather comprises a substantial union proper to man alone. Aquinas’ account of the soul follows Aristotle’s on this point, maintaining that, “it is with respect to the intellective soul that we are said to be men; to the sensitive soul, animals; to the nutritive soul, living beings.” Descartes’ attack on Aristotle in the Meditations first addresses, and then overturns specific Aristotelian doctrines with the intention of starving out the roots of Aristotelian first philosophy by destroying its branches — namely, the somatic and psychic doctrines associated with Aristotle’s conception of man. Aristotle’s doctrine that states, “the soul never thinks without an image” is connected in every respect with the doctrine of the soul as the form of the body, and with his conception of man as a rational animal.
Descartes does not recognize the validity or the self-evident empirical nature of Aristotle’s first principles. On the contrary, his refutation in the Second Meditation of the Aristotelian doctrine that the soul never thinks without an image sets up a reductio ad absurdum chain of reasoning that destroys Aristotle’s conception of man by calling into question the reliability of the senses to convey any true knowledge to the understanding. If Descartes rephrased Aristotle’s doctrine of cognition, it might have read something like, “the soul knows nothing through the medium of an image.” Indeed, the meditator discovers that the mind’s essential understanding of objects only resembles the world of material objects. Accordingly, Descartes infers that “what is called ‘having sensory perceptions is strictly just… thinking.”
In the First Meditation, Descartes’ hypothesis of the ‘evil genius” [malin genie in the French edition] raises Pyrrhonian skepticism to a new pitch of intensity. If it were the case that all knowledge, and the faculties for acquiring and judging knowledge, were under the influence of some malicious deceiver “of the utmost power” [summe potens], the mind’s criterion for examining its ideas, and the source of its ideas is open to question on every conceivable level, and at every point. The force of Descartes’ argument lies in the fact that it would be impossible for the mind to know or tell if it were under the control of a most powerful deceiver. The Aristotelian theory of cognition, which emphasizes the primacy of the individual senses and their particular objects in the process of “coming to know,” has no defense against Cartesian skepticism. Descartes’ cogito necessarily has neither a basis in, nor any reference to the world of material particulars. In the Second Meditation, Aristotle and his 17th century adherents are parodied by Descartes in such questions as, “What then did I formerly think I was? A man. But what is a man?”, “what is an animal?”, and “what is rationality?” Descartes concludes that he “does not now have the time to waste on subtleties of this kind.” Under Descartes’ hypothetical circumstance, grounds for discovering any epistemological certainty are theoretically impossible.
THE PROBLEM OF DESCARTES’ TERMINOLOGY AND THE ATTACK ON THOMAS AND SCHOLASTICISM IN THE MEDITATIONS
In the Meditations, the doctrine of the cogito, flanked by the doctrine of “the mind alone inspects,” represents a thoroughgoing epistemic critique of the Aristotelian empiricist doctrine of “the soul never thinks without an image.” That Descartes overturned centuries of philosophical reliance on Aristotelian physics and metaphysics is well documented in the literature of the history of ideas. What is less obvious is whether Descartes’ attack on the philosophy of Aristotle in the Meditations was meant as a covert attack on the philosophy of St. Thomas. We can ask whether Descartes’ self-professed intention of offering the Meditations to the Dean and Doctors of the Sorbonne as work in the grand Scholastic tradition of giving demonstrative proofs for the existence of God and the immortality of the soul can be taken at face value.
In both the Meditations and the Discourse on the Method, Descartes’ attack on Aristotelian realism is waged, in part, through the terminology he adopts to undermine the claims of Aristotelian philosophy. For example, certain recognizable Aristotelian phrases and terms occur in the Meditations, such as “rational animal,” “power of self movement,” “common sense,” “nutrition,” and “imagination.” Descartes’ technical use of these terms and phrases were no doubt adopted for either one or both of the following reasons. First, the term “imagination” and the phrase “rational animal” are characteristic of the language of the Scholastic opponents Descartes is attempting to refute. By employing the Aristotelian language, Descartes caricatures his opponent’s views. The second reason that Descartes adopts the Aristotelian terminology, particularly in the Second and Sixth Meditation, is likely because of the fact that no other terminological apparatus was available in the 17th century. Moreover, the philosophical tradition frowned upon the invention or introduction of novel terms for the sake of novelty. As previous commentators have noted, Descartes’ terminology in the Meditations contains next to nothing in the way of novelty. Only his unique redefining of the battery of pre-existing Ancient and Scholastic terms can be said to be original. Descartes’ acceptance of what the primary goals of philosophy are, as well as the standard array of terminology, as handed down from both the Ancients and their Scholastic descendants, is explicitly present in the Meditations.
Even Descartes’ earliest commentators and critics recognized his subversive use of Aristotelian/Scholastic terminology in the Meditations. When Descartes topples Aristotelian realism in the Second Meditation by demonstrating that the nature of the soul/mind can be asserted as an object of knowledge prior to the knowledge of bodies, he is attacking the classic Aristotelian doctrine of “the soul never thinks without an image.” As a close reader of the writings of Aristotle, Descartes was likely acquainted with the phrase, “the soul never thinks without an image.” However, when the Meditations and the Discourse on the Method are searched for the classic Aristotelian phrase, one finds that Descartes never uses the phrase as it occurs in Aristotle’s writings. In the fourth partition of the Discourse on the Method, Descartes has instead rendered into French a Scholastic variant of Aristotle’s phrase:
“…there is nothing in the intellect which has not previously been in the senses [qu’il n’y a rien dans l’entendement qui n’ait premierement este dan le sens].” Again, in the Sixth Meditation we find it worded thus: “In this way I easily convinced myself that I had nothing at all in the intellect which I had not previously had in sensation [facile mihi persuadebam nullam plane me habere in intellectu, quam non prius habuissem in sensu].”
In the latter two examples, Descartes employs what previous commentators have noted to be a Scholastic variation on Aristotle’s phrase. As these commentators indicate, a likely source for the variation used by Descartes is the writings of St. Thomas.
In Thomas’s writings we find a variation on Aristotle’s phrase that silently introduces the terminological and verbal modifications that Descartes was to later adapt into his writings: “There is nothing in the intellect that is not previously in the senses” [nihil est in intellectu quod non sit prius in sensu]. Although Thomas nuances the phrasing of the established idiom, he does so without corrupting Aristotle’s empirical doctrine. The question arises: if, in his Discourse on the Method and the Meditations, Descartes’ use of the phrase as it occurs in Aquinas’ writings is deliberate, is it meant as a shrewd critique of the Doctor angelicus? Does Descartes inadvertently strike a blow at the foundation of Catholic orthodoxy by refuting Aristotle via the doctrines of Thomas?
To the extent to which Thomas’ conception of the soul agrees with or derives from Aristotle’s account of the soul, this is the conception of the soul Descartes attacks in the Second Meditation. However, Descartes’ proof for the separabilty of the mind from the body, or of the mind’s self-subsisting nature, agrees with Thomas’ account of the separable soul, on the point that both are an affirmative answer to the Christian theological imperative to uphold the doctrine of the immortality of the soul. We may point out, however, that the theological imperative to argue for the soul’s immortality was not present for Aristotle as it was for Thomas. While there are passages in De anima that seem to promote the idea of the rational soul possessing an immortal nature, other passages clearly associate the mortality of the body with the mortality of the soul. Yet in De anima Aristotle states that, “that while the faculty of sensation is dependent on the body, mind is separable from it.” It was a matter of dispute among the Scholastics whether Aristotle meant that the intellect only engages in operations in which the body has no part, as when he writes that, “…some [parts of the soul] may be separable because they are not the actualities of any body at all.” Also open to dispute among the Scholastic philosophers was Aristotle’s opinion on whether the rational soul could be classed as a substantial form: “When mind is set free from its present conditions it appears as just what it is and nothing more: this alone is immortal and eternal… mind in this sense is impassable… and without it nothing thinks.”
In any case, the question whether the soul survives the body’s death, and whether the rational or intellectual soul is mortal or immortal necessitated Thomas’ chief modification to the Aristotelian conception of the soul. Indeed, Thomas’ modification involved altering the ontological status of the rational soul, thus disengaging it from the questions of mortality and substantiality. The soul, according to Aristotle, is a faculty of thought that makes up a substantial form only when united to the matter of the human body. In Thomas’ account of the rational soul, he argues that the soul itself is a substantial form in its own right. That is, the intellective soul is non-destructible, self-subsisting and immortal by definition. Yet the conversion of a rational faculty of thought into an intellectual substance does not resolve the inherent difficulties in how the separable soul operates after the death of the body, since Thomas retains the Aristotelian doctrine that “there is nothing in the mind that was not previously in the senses.” In sum, the active and possible intellect, and the bodily sense organs on which the soul depends for the delivery of its proper object are inseparably connected.
DESCARTES’ CONCEPTION OF MIND VERSUS THE SCHOLASTIC CONCEPTION OF THE SOUL
The question of the soul’s immortality in Descartes’ Meditations is a reiteration of a long-standing theme of the Scholastics. The means by which Descartes goes about proving the immortality of the soul constitutes a departure from the accepted convention of either lending ultimate support and authority to a rational proof of the soul’s immortality. In his Sorbonne letter, Descartes cites relevant passages from Scripture and rejects the teaching that no rational proof of the soul’s immortality is available to the natural light of reason alone, as did Duns Scotus and William of Ockham. In any case, no Scholastic discussion of the soul’s immortality ever sought to supplant the doctrine of immortality that the Church maintained is revealed through the Scriptures, and held as a verity of religion by faith alone. Scholastic proofs adduced for the existence of God or the immortality of the soul were “demonstrated” a posteriori to the belief that God exists and that the soul is indeed immortal — that is, these proofs assume the validity of what they have yet to prove.
Descartes’ demonstration of the existence of God in the Third Meditation is an a priori proof that precludes the presupposition of any “long-standing opinion that there is an omnipotent God,” and proceeds from the starting point that “everything said about God is a fiction,” including his existence. Similarly, Descartes’ proof for the separability of the mind from the body in the Second Meditation begins with the meditator’s categorically doubting the existence of all extended bodies in order to uncover, in the order of being, the nature of the soul per se.
The investigation of the soul, under the respective considerations of Aristotle and his Scholastic followers, had traditionally begun with sensible particulars, applying an inductive method of examination to such phenomena as the perceptible self-movement of living things, and proceeding to inquiring as to the cause of movement. The somatic psychology of Aristotle and the Scholastic philosophers offers a naturalized account of the soul. As the form of the body, the soul of man is a rational faculty that depends on the sense’s apprehension of material particulars in order to operate. Knowledge, in this sense, is essentially embodied, and in De anima, Aristotle writes that the soul has been justly referred to as “the place of forms,” on account of the fact that the rational intellect has no organ, and hence no operation apart from the medium of the phantasms intuited by the sense organs.
According to Aristotle’s account of the soul, the nature of the substantial union of the soul and body is a union of such a kind that the corruption of the instantiated soul cannot occur without corruption coming to the body as well, and vice-versa. Plato’s celebrated metaphorical image of the relation between the soul and body as a sailor in a ship is a negative example in Aristotle’s usage, for the union between soul and body is not such that the soul directs the movements of the automaton body in which it is emprisoned. What connects the soul and body in Aristotle’s account, and in Thomas’ account as well, is the fact that the intellectual soul requires the faculties of imagination and sensation in order to operate, and imagination and sensation are carried out through corporeal organs; hence, as Thomas puts it, the formal principle, the soul, and the material principle, the body, are “joined together in the unity of one act of being.”
THOMAS’ CONCEPTION OF THE IMMORTALITY OF THE SOUL
For Descartes, the emphasis in the Sixth Meditation is on the problem of how the soul is joined to the body, and stands in contrast to the operations of the pure understanding (Meditation Two), where the mind is shown to function independent of any attachment to a body, and is thus by definition separable. For Thomas, the soul is joined in a substantial union with the body, and the existence of bodies is self-evident, and therefore indubitable. Regarding the question of the soul’s immortality, Thomas emphasizes the issue of the soul’s separability from the body. The intellectual soul first needs to be demonstrated as substantial per se. Substantiality, according to Aristotle, is tantamount to self-subsistence and impassibility, and the status of substantiality that Thomas grants to the intellectual soul provides the gateway for his proof of the soul’s immortality.
Generally, then, the difference between Descartes’ revival in the Meditations of the question of immortality addressed by Thomas and other the other Scholastic philosophers is the question of how the soul’s immortality can be demonstrated. Descartes agrees with the Scholastic philosophers about the immortality of the soul. The point at which Descartes diverges from Thomas and the Scholastics is in method rather than principle. The meditative exercise of withdrawing the mind from the senses is an epistemological method that neither Aquinas nor any other Scholastic philosopher ever employed to arrive at the conclusion that the intellectual soul is separable from the body, and that God exists.
The efforts of Thomas Aquinas to solve Aristotle’s open question of the immortality of the soul involved modifying two notable doctrines of Aristotle. The first point, that the soul is the form of the body, argues that the soul and the body form a substantial composite that cannot be split apart or corrupted without destruction coming to the whole. Hence, neither the body nor the soul is self-subsisting, due to the function of each being wholly dependent on the other part for its respective operation. Briefly then, the rational soul that animates the human body, and the sense organs of the human body that supply the rational soul with phantasms, from which operation all intellectual knowledge derives, are co-constitutive. Man, in the last analysis, is human on the condition that he comprises a particular substantial combination of rationality and animality.
It follows from this that decay in the function of the sense organs, or the total demise of the body, erects an insuperable barrier between the operation of the rational soul, and the sense object upon which its operation depends. There is indeed nothing for the rational soul to think without the senses first receiving the phantasm of a sensible object. On two counts, then, it would seem that the soul could not legitimately be a substance by definition; first, by virtue of the material nature of the sense organs, and second, by virtue of the phantasm’s origination in corporeal objects.
Thomas begins to resolve the question of the soul’s apparent mortality by establishing the soul’s subsistence thus:
I answer that, it must necessarily be allowed that the principle of intellectual operation, which we call the soul of man, is a principle both incorporeal and subsistent. For it is clear that by means of the intellect man can know all corporeal things. Now, whatever knows certain things cannot have any of them in its own nature, because that which is in it naturally would impede the knowledge of anything else… Now every body has its own determinate nature. Therefore it is impossible for the intellectual principle to be a body. It is also impossible for it to understand by means of a bodily organ, since the determinate nature of that organ would likewise impede knowledge of all bodies…
A number of important points are asserted here. First, Thomas writes that the substantial composite of the body and soul (the soul being the form of the body) is separable. Second, he asserts that this separation does not impede the action of the intellective operation of the soul. Last, it follows from this that the operation of the bodily senses that the gathering of phantasms is not essentially prior to the operation of the intellectual soul. Following Aristotle, Thomas proceeds to elaborate the separability of the intellectual soul from the body by making a crucial distinction between the operations of the soul that are dependent on the senses, and those operations of the soul in which the corporeal sense organs have no part, such as understanding and willing:
Therefore the intellectual principle, which we call the mind or the intellect [mens vel intellectus], has essentially an operation in which the body does not share. Now only that which subsists in itself can have an operation in itself. For nothing can operate but what is actual, and so a thing operates according as it is… We must conclude, therefore, that the human soul, which is called intellect or mind, is something incorporeal and subsistent.
Sense images are the first principle of the intellectual soul’s knowledge, but the action of the intellectual soul is rendered neither substantial nor mortal according to the mode by which it wills and understands; rather, this is precisely the point by which the intellectual soul is known to be separable and self-subsisting after the death of the body. Thomas likens the per se mode of understanding in the separated soul to a similar mode of understanding found in separate substances. The separated soul, like the separate substance, receives a “more abundant influx” of those objects known only by the pure understanding, and furthermore, Thomas asserts that,
…the more the soul is freed from preoccupation with its body, the more fit does it become for understanding higher things… Consequently, when the soul shall be completely separated from the body, it will be perfectly likened to separate substances in its mode of understanding, and will receive their influx abundantly.
This fragment provides an outline of the intellectual soul in a state of separation from the body; but a disembodied state is not the existence proper to the intellectual soul, defined as such, and Thomas points out that the existence of the intellectual soul neither predates its being united to a body, nor will it subsist apart from the body without end, but it will instead be clothed once more with an imperishable body; and in this is the separated soul wholly distinctive in its mode of being from separate substances.
THE MIND’S SEPARABILITY VERSUS THE SOUL’S IMMORTALITY
Concerning the survival of the incorporeal soul after the dissolution of the body, Aristotle does not give a consistent opinion in De anima, except on the point that the rational soul is “capable of existence [i.e., functioning] in isolation from all other psychic powers [i.e., those faculties of the soul involving such things as nutrition and sensation].” The demonstrable fact that the rational soul engages in operations such as calculation, speculation and contemplation, in which the body has no share, is not tantamount to the Thomistic claim that the soul has an existence — not merely an operation — entirely independent of the body that it is the form or actuality of. If the human intellectual soul, as the actuality of the human body, possesses operations that are in no way dependent on the body’s operations, then it follows that the intellectual soul is capable of continuing its operation of intellectual apprehension (intelligere corrumpitur) after the dissolution of the body.
In his Summa Contra Gentiles, Thomas arrives at conclusions about the human intellectual soul that are contrary to the views of Aristotle. Thomas iterates Aristotle’s conception of the soul that has no operation apart from the body:
Further, if the soul were something subsistent, it would have some operation apart from the body. But it has no operation apart from the body, not even that of understanding; for the act of understanding does not take place without a phantasm, which cannot exist apart from the body.
Thomas offers two solutions to the problem of how the soul in a state of separation from the body operates. Thomas’ first answer situates the problem in a specifically Christian context: the resurrection of the body and the reuniting of body and soul is a tenet of the orthodox Christian faith, and Thomas was bound to uphold its truth. The second answer, also supporting the resurrection of the body, is found in Thomas’ demonstration:
…the soul is naturally united to the body, for in its essence it is the form of the body. It is then contrary to the nature of the soul to be without the body. But nothing which is contrary to nature can be perpetual. Perpetually, then, the soul will not be without the body. Since, then, it persists perpetually, it must once again be united to the body; and this is to rise again. Therefore, the immortality of souls seems to demand a resurrection of bodies.
Considering that the dubitability of the evidence obtained through the senses calls into question the validity of any proof presupposing the reliability of the senses (such as Thomas’ proofs for the existence of God and the immortality of the soul), Descartes considered finding indisputable proofs for the existence of God and the separability of the soul from the body of particular importance. Descartes maintains that such a posteriori proofs are inconclusive because man’s knowledge of ontological objects is made to depend on the perception of the fallible senses as the first principle of knowledge.
In his letter to the Dean and Doctors of the Sorbonne, Descartes claims that the existence of God and the immortality of the soul “are prime examples of subjects where demonstrative proofs ought to be given with the aid of philosophy rather than theology;” and further,
…that the only reason why many irreligious people are unwilling to believe that God exists and that the human mind is distinct from the body [mentemque humanam a corpore distingui] is the alleged fact that no one has hitherto been able to demonstrate these points.
That no prior proof for the existence of God and the immortality of the soul is immune to contradiction or refutation is precisely what Descartes is claiming to be the case, stating that, “I would add that these proofs are of such a kind that I reckon they leave no room for the possibility that the human mind will ever discover better ones.”
However, a rational proof for the existence of God and the immortality of the soul would invalidate the necessity for God’s participation in revealing Himself to man. Nor would the soul’s survival or salvation require God’s grace or intervention after the death of the body. Aquinas was particularly aware of the fideistic dimension to the question of the soul’s immortality. If the self-subsistence of the soul could be conclusively demonstrated, then God’s act of preserving the soul after the body dies would be rendered unnecessary, since the soul would invariably be immortal, and would not need divine support to secure its subsistence.
In the dedicatory epistle to the Sorbonne, Descartes maintains that man’s rational knowledge of the true distinction of the mind and body is an antecedent evident enough to validly deduce the soul’s immortality as a consequent, without any further recourse to the Scriptures or the teaching of the Church. In a letter to Mersenne on December 24, 1640, roughly four months before the Meditations received its finishing touches, Descartes responded to Mersenne’s disappointment at not finding the immortality of the soul demonstrated as promised in the proofs of his Meditations:
You say that I have not said a word about the immortality of the soul. You should not be surprised. I could not prove that God could not annihilate the soul, but only that it is by nature entirely distinct from the body, and consequently it is not bound by nature to die with it. This is all that is required as a foundation for religion, and is all that I had any intention of proving.
As a theological matter, the immortality of the soul is guaranteed by an act of faith in what the divinely revealed Scriptures declare to be true, rather than reason’s discovery that the soul persists after the death of the body. Descartes’ statement that a philosophical demonstration that the operations of the mind are distinct from the mechanical operations of the body does not violate or infringe upon the domain of the soul’s immortality as a religious doctrine held by faith. As the doctrines of the Church command the faithful to believe without rational or visible proof, Descartes’ reproach of Mersenne for his improbable expectation that the Meditations would contain a certain proof “that God could not annihilate the soul” is in accord with the doctrinal mystery of the soul’s immortality.
Philosophically, Descartes justifies the consequent that the soul “is not bound by nature to die” with the body with his demonstration in the Second Meditation of the mind’s separability from the body. Descartes is not ignorant that since the soul’s immortality is a religious question of fundamental doctrinal importance. However, the issue of whether God can or cannot annihilate the soul is ultimately a theological concern that goes beyond what is “required as a foundation for religion.” According to Descartes, a foundation for religion is simply no more than adherence to the tenets and doctrines as established by the Church. In his letter to Mersenne in December 1640, Descartes addresses a charge regarding “to what extent the immortality of the soul can be demonstrated in light of man’s necessarily incomplete knowledge of the infinite will and mind of God”:
…you [Mersenne] go on to say that it does not follow from the fact that the soul is distinct from the body that it is immortal, since it could still be claimed that God gave it such a nature that its duration comes to an end simultaneously with the end of the body’s life. Here I admit that I cannot refute what you say. For I do not take it upon myself to try to use the power of human reason to settle any of those matters which depend on the free will of God.
The consideration given so far to those features of the Cartesian doctrine of the mind’s separability from the body, and the fact that the doctrine was a reaction to Scholasticism, open up the question of whose conception of the separated soul Descartes’ account better corroborates. Aristotle claims in De anima that mind is separable from the body, but what status it holds after the death of the body is ambiguous. Thomas deduces the immortality of the soul from the fact that it is separable from the body. The answer to this question does not lie in the novelty of the idea of the soul’s separability from the body, for this idea is common to Aristotle, Aquinas and Descartes. The answer lies in Descartes’ hesitancy to attach to his doctrine of the mind’s separability from the body the immortality of the soul as a necessary or a logical consequent.
Even though Descartes’ account of the soul in the Meditations agrees with Aquinas’ account of the soul on the point that the Church’s dogma of the immortality of the soul established a necessary starting point for both philosophers, the vision of the human soul in the Meditations is a secularized one, stripped of its sacred origins and theological definition. Under Descartes’ considerations, the beatitude of the soul is not a necessary consequence of its separability from the body any more than that the soul be the individuating or animating principle of any specific kind of body. The rational mind could just as easily be housed in the body of an ass, as in Apuleius’ Metamorphoses.
Descartes’ proof for the separability of the mind from the body contains a nominalistic tendency wholly lacking in Thomas’ account of the separated soul. In the Synopsis of the Meditations, Descartes maintains that “the premises that lead to the conclusion that the soul is immortal depend on an account of the whole of physics,” which, in Aristotle’s and Thomas’ minds, includes final causes. In the Fourth Meditation, Descartes states,
For since I know that my own nature is very weak and limited, whereas the nature of God is immense, incomprehensible and infinite, I also know without more ado that he is capable of countless things whose causes are beyond my knowledge. And for this reason alone I consider the customary search for final causes to be totally useless in physics; there is considerable rashness in thinking myself capable of investigating the [impenetrable] purposes of God.
If we read the fragment from the Synopsis into the passage from the Fourth Meditation, it becomes apparent why a demonstration of the immortality of the soul is impossible. The nature of such a demonstration would mean answering the question of why the soul is not by nature bound to die with the body, which would be the same as grasping the final cause, or end, of the soul separated from the body.
In the Second Meditation, the soul’s separability from the body is accounted for from within the order of essential causality in a way strikingly similar to the means by which the meditator in the Third Meditation proves the existence of God from the essential order of causation. This in turn accounts for the reason why the meditator is able to “perceive that likeness, which includes the idea of God, by the same faculty which enables me to perceive myself.” Descartes pays no mind to the reasons for why the soul is separable from the body, only the means of how it is, or can be known to be separable, which he demonstrates in the Second Meditation with the example of the wax. In his thought experiment, the essential nature of the wax is perceived by detaching the mind from the senses (abducere mentem ad sensibus), and the experiment concludes with the doctrine that the mind alone inspects (sed solius mentis inspectio) the essential nature of objects as ideas.
However, there is no account in the Meditations of the final cause of the mind separated from the body. Descartes gives his reason: “I have tried not to put down anything which I could not precisely demonstrate.” The ideas innate in the mind are secondary to God, who is the first cause in the order of causes. Descartes characterizes all ideas as secondary causes throughout the Meditations. The case with Descartes’ proposition that the investigation of final causes in physics is useless covers the same ground as the inscrutable futures of Thomas’ separated soul. To give an account of final causes in physics would be probing into the infinite and incomprehensible nature of God. If man is incapable of accomplishing that, then his knowledge of how the soul will subsist in a future state can be illuminated no further.
Descartes regarded the defense of the dogma of the immortal soul of man as a theological responsibility more than a philosophical one. That the soul of man is imperishable is a teaching and dogma of the Church known by the light of Scriptural revelation, and held to be true by the light of faith alone. Descartes’ demonstrative proof in the Second Meditation that the soul “is not bound by nature to die” with the body can never amount to an indubitable guarantee that the soul is not bound by nature to die with the body. The rational soul is not necessarily immortal, but it is, as Descartes demonstrates, separable. Considered independent of its Scriptural and theological underpinnings, the doctrine of the separabilty of the mind from the body is a doctrine no more specifically Christian than the proof for the existence of God as an innate idea in the mind in the Third Meditation is the same God as that of Abraham, Isaac and Jacob.
When confronted with the theological implications of his philosophic doctrines, Descartes expressed little more than diffidence towards spinning out the theological implications of the philosophic doctrines established in his Meditations. He was aware that he would have show how the principles of his philosophy could either establish that the truths of faith and the truths of reason are not mutually contradictory, or that his philosophy lends explanatory support to the type of theological issues “where it is notoriously difficult to reconcile philosophy to theology,” such as the doctrine of transubstantiation in the Eucharist. As a theological matter, the immortality of the soul is not guaranteed by the powers of reason’s discovery that the soul persists after the death of the body. The doctrine of the immortality of the soul is, properly speaking, an act of faith in what the divinely revealed Scriptures declare to be true. Descartes’ statement that a philosophical demonstration of the fact that the operations of the mind are distinct from the mechanical operations of the body does not violate or infringe upon the domain of the soul’s immortality as a religious doctrine held by faith. As the doctrines of the Church command the faithful to believe without rational or visible proof, Descartes reproach of Mersenne for his improbable expectation that the Meditations would contain a certain proof “that God could not annihilate the soul” is in accord with the doctrinal mystery of the soul’s immortality.
Philosophically, Descartes justifies the consequent that the soul “is not bound by nature to die” with the body with his demonstration in the Second Meditation of the mind’s separability from the body, reminding Mersenne that since the soul’s immortality is a religious question of foundational importance doctrinally. For Descartes, however, the issue of whether God can or can not annihilate the soul was ultimately a theological concern that goes beyond what is “required as a foundation for religion,” which is simply no more than adherence to the tenets and doctrines as established by the Church.
The Church’s doctrine of the soul’s immortality, as derived from the teaching of Thomas, underwent a radical transformation in the Cartesian synthesis of the Scholastic doctrine of the immortality of the soul with the epistemic critique of knowledge. In the Synopsis of the Meditations, Descartes asks his readers not to mistake his proof for the mind’s separability from the body as a demonstration of premises that he does not endeavor to prove. These premises are those “which lead to the conclusion that the soul is immortal,” and which depend for their validity on “an account of the whole of physics,” or, in other words, the clear knowledge “that absolutely all substances, or things which must be created by God in order to exist, are by their nature incorruptible and cannot ever cease to exist unless they are reduced to nothingness by God’s denying his concurrence to them.”
Descartes aimed to give an account of the whole of physics, and thereby establish the immutability of the laws governing the universe. However, in order to accomplish this, Descartes needed to prove, as he endeavors to do in the Meditations, that God, while not bound to abide by the laws that He has instantiated in creation, is not a deceiver, and therefore will not alter or change laws He has established. The clarity and distinctness of the mind’s perceptions of its own ideas is the benchmark for determining that not only does God exist, but also that the mind is separable from the body. Recalling Descartes’ letter to Mersenne in December 24, 1640, we can conclude that what is at stake in an irrefutable proof of the soul’s immortality is whether the soul is by nature immortal, and without any need for God to lend His concurrence for it to survive, or whether the soul does require God’s intervention to survive. Descartes concedes that the survival of the soul after the death of the body presents too large a task for philosophy to accomplish:
I could not prove that God could not annihilate the soul, but only that it is by nature entirely distinct from the body, and consequently it is not bound by nature to die with it.
DESCARTES’ MIND AND THOMAS’ SEPARATE SUBSTANCES
Descartes’ doctrine of the mind’s innate knowledge of essences states that the mind or understanding knows or inspects those ideas that are innate within it. Accordingly, once the soul is separated from the body, its mode of understanding is not mediated or impeded by anything external to it. On the contrary, according to Thomas, the intellectual soul depends on intelligibles taken from sensible things in order to activate the understanding, or possible intellect. However, when in a state of separation from the body, the soul
will understand through itself, in the manner of substances which in their being are totally separate from bodies… And from those substances… the separated soul will be able to receive a more abundant influx, productive of a more perfect understanding on its own part.
Since Aristotle did not consider the rational soul to be a substance in its own right, it was a necessary precondition of Thomas’ ontology to demonstrate that the soul is a substance. Thomas accepted Aristotle’s doctrine of the soul as the form of the body, as well as his doctrine that the body and soul are united in a substantial union; the question that remained for Thomas was, how is it possible to divide an indivisible substantial union without corruption coming to the whole? Thomas’ answer was this: while the body is itself divisible, being a composite of matter and form with many accidental parts and qualities, the intellectual substance, which is not composed of matter and form, is indivisible since “all corruption occurs through the separation of form from matter.” When the intellectual soul is separated from the body, its substantial character, its per se unity, persists in the same respect that “roundness is in a circle through itself, but is by accident in a coin; so that the existence of a non-round coin is possible; whereas it is impossible for a circle not to be round.”
In Thomas’ Summa Contra Gentiles, the discussion of separate substances (angels) comes right after his considerations concerning the union of the human body to the intellective, or rational soul. Thomas’ discussion of separate substances treats the question of whether a form can exist apart from matter; and if so, what sort of nature that form would have:
That which is by itself [per se] must be prior, in the order of being, to that which is by accident [per accidens]; incorporeal intellectual substances [or separate substances] exist per se, while material being exists per accidens; there must exist intellectual substances, prior in nature to souls, which, by virtue of the nature of their being, enjoy a higher substantial form without participation in a lower material nature.
A comparison of Descartes’ rational soul to Thomas’ separate substances can be made under the following points. First, Descartes’ rational soul differs in the order of existence from Thomas’ separate substance in the respective degrees of perfection accorded them by their Creator. The rational mind of man is the highest grade of intelligence accorded to the sphere of corporeal nature. The intellect of separate substances is more perfect than man’s intellect, yet they are less perfect than the intellect of God in the sphere of intellectual nature. In the case of man, angels, and God, the difference in intellect is one of quantity as measured by infinity. Man’s rational mind is to an angel’s as a finite nature is to an infinite nature; and the intellect of angels is distinct from the intellect of God, again, magnified by an infinity. Hence, intellect in the order of existence can be measured on a scalar magnitude of perfection, from highest to lowest.
The second point of comparison of Descartes’ rational soul to Thomas’ separate substances comes from Descartes’ hypothetical consideration of an angel joined to a human body. Writing to Regius, Descartes states that, “if an angel were in a human body, he would not have sensations as we do…” The reason that an angel in a human body would no have sensation is because of the distinction between the rational soul and Thomas’ separate substance, namely, the respective mode of understanding that each enjoys, but does not share with the other. The nature of the act of understanding in rational soul and separate substance can be distinguished in terms of their respective objects. Separate substances apprehend intellectual things because they are intellectual natures; they do not uncover the intelligible buried in the sensible by means of abstraction, which is the mode of the rational soul inhering in a material nature. The respective mode of understanding of the rational soul and the separate substance is marked by the difference between discursive reasoning and a priori reasoning. An intellectual nature does not acquire a sensitive soul merely by means of accident, and vice versa. Sensation in the human body is a necessary component for the rational soul’s mode of understanding, because sensation is the means of the rational soul’s acquiring its object, viz., intelligibles, by means of phantasms. Accidental properties inhering in matter individuate things, and the task of the rational soul is to abstract from material particulars in order to make them intelligible to itself. The perception of a plenary of distinct objects does not amount to categorical knowledge; that is to say, knowledge of universals. Thus, sense perception is the first principle of human understanding, and via a series of channels, we come to knowledge of things per se, or free of matter. The mode of understanding for angels, on the other hand, is not discursive or subject to the vicissitudes of corporeal organs, but rather a perception of intelligibles per se. Thomas states that angels know material things, and further, that they know particular material things. But this scale of intellective competence is not vertical; rather it is descending. The higher species (i.e., a specific kind of intellectual nature) must contain in some way, and to a greater degree of perfection, what is contained in the lower (e.g., a form in material nature). Whatever exists in material substance in a material way is present to intellectual substance in an intelligible way. Accordingly, angels, and God for that matter, do not require corporeal sense organs in order to know particular material things. Because there is no principle in nature that unites an intellective nature whose mode of understanding is pure to an intellective nature whose mode of understanding depends on bodily senses, it is unnecessary, as it is impossible for an angel to dwell in a body.
Thomas’ rational soul in a state of separation from the human body does not make a good parallel to the embodied/disembodied Cartesian mind for the following two reasons. First, God must preserve the separated soul after the death of the body. Without Divine support to conserve it, the separate soul has no more way of existing than members of either the vegetative or the nutritive category of soul. Second, Thomas’ separated souls require “an influx of divine species” to understand. In other words, to know anything at all, separated souls require images that come from something besides material objects of perception. God must both conserve and feed images to the human mind after the death of the body. Consider Thomas’ own comparisons of separated souls to separate substances:
To exist apart from bodies is an accidental competence on the part of souls, since they are naturally the form of bodies — this indicates that intellectual substance is neither equivalent to the rational soul of man, since it does not inhere in any material form, nor, on the contrary, do souls, after the body dies, qualify as substance occupying a corresponding division of existence to that of intellectual substances.
The characteristic act of intellectual substances is the act of understanding; we can specify the nature of this act from its object: things can be grasped by the intellect insofar as they are free from matter. Separate substances apprehend intellectual things because they are intellectual natures; they do not uncover the intelligible buried in the sensible by means of abstraction.
Concerning the origin of the Cartesian mind, Thomas’ separated souls bear a certain likeness to Descartes’ concept of mind, but fail to explain many characteristic features of the Cartesian mind, such as the fact that the rational mind does not require external objects of perception to know anything. The noetic contents of the Cartesian mind are not activated by external objects of perception. The Cartesian mind understands all concepts per se, without mediation, and it does not cease to understand when in either a temporary or a permanent state of separation from the body.
We have shown that Descartes’ rational mind is comparable to something like Aristotle’s rational soul turned inside out. To find a likely source for the origin of the Cartesian mind, another source closely allied to Aristotle’s rational mind must be considered— Thomas’ separate substances (otherwise known as angels ). The superior correspondence of Thomas’ separate substances to Descartes concept of mind can be seen in Thomas’ contrast between the separated soul and the separate substance’s respective mode of understanding:
The operation of understanding exercised through a corporeal organ is an imperfect means by which to understand. The substance of a thing must be commensurate to its operation, and understanding is the only proper operation of an intellectual substance… intellectual substances have no need of a body to apprehend their object [i.e., insofar as intelligibles are taken from material things, the faculty of understanding is imperfect, as is the case with the rational soul]. The proper objects of intellectual substance are things that in their very nature are intelligible, or things that are intelligible in themselves. In contrast, objects grasped by rational souls are things known by the intellect through the intermediary means of phantasms [i.e., images of objects of sense perception] received through sense organs. So, things in this way are not known through themselves, but through abstraction [i.e., conceptually].
Accordingly, Thomas himself argues that his separate substances are not equivalent to Aristotle’s rational soul. Separate substances are not formed of a compound of soul and body, while the rational soul, as Aristotle defines it, is always the form of the human body. Thomas’ separate substances bear a far greater likeness to the Cartesian mind in the respect that separate substances understand all essences directly (thus, they know material things and singulars as well ), and they understand without Divine mediation. From here we can draw the further parallel of the Cartesian mind to the Divine mind.
THE CORRESPONDENCE OF THE MIND OF GOD AND THE RATIONAL MIND IN THE MEDITATIONS
In order to build a case in his letter to the Sorbonne for the proof for the existence of God he gives in the Third Meditation, Descartes draws on Biblical citations that assert man’s knowledge of the existence of God to be “manifest.” Indeed, Descartes’ proof for the separabilty of the soul from the body in the Second Meditation hinges dialectically on his proof for the existence of God as an innate idea of the mind in the Third Meditation. Descartes’ substitution of the Scholastic term “soul” with the term “mind” is present in the Sorbonne letter, and so too is his doctrine of innate ideas: “everything that may be known of God” through the Scriptures, including man’s knowledge of God’s existence, “…can be demonstrated by reasoning which has no other source than our own mind.”
Descartes’ curious phrase, “no other source than our own mind,” introduces a subtle shift in his argument to the Sorbonne Dean and Doctors. Man’s empirical knowledge of the existence of God, according to Thomas and his 17th century adherents at the Sorbonne, is derived from God’s sensible effects throughout His creation. Under the idealist auspices of the Cartesian method, Thomas’ empiricism is abrogated to the realm of a fiction of the mind. According to Descartes, the mind’s knowledge of God’s existence is not discursive. According to Descartes, the Aristotelian/Thomistic claim that the mind’s knowledge of the existence of God can be derived from His sensible effects is a fallacy in the order of knowledge. The corporeal organs of sense only sense what is sensible; and God, who is incorporeal, cannot be apprehended in His existence through the corporeal senses. The dubitability of the objects of sense perception undermines the validity of knowledge derived from the material world. If man’s knowledge of the existence of God is drawn from sensible effects, then the existence of God can be called into doubt through the same channels by which His existence was asserted. Famously, Descartes does precisely this in his Mediations. Yet what was taken as evidence of Descartes’ atheist-skepticism by his critics was in reality Descartes’ rejection of Aristotle and Thomas’ rational soul that understands itself though the senses in favor of the understanding of the undiluted rational mind. The question of how good a Catholic was Descartes becomes clear when it is realized that the answer has nothing to do with religion, and everything to do with competition between schools of thought. Competition between the Aristotelian and Platonist/neo-Platonist schools of thought was extremely wide-ranging in the 17th century. The Church’s shadow over intellectual life has been equally over-exaggerated by both commentators and historians of philosophy. In 1641, Descartes celebrated the birth of his mechanical man animated by William Harvey’s discovery of the heart that pumps blood. Such a conception of man represented a triumph over Aristotle’s rational soul animated by the fantasy of phantasia, not a victory over the claims of man’s revealed religion.
Of the three types of intellect treated in Descartes’ writings (Divine, angelic, and human), it is the Divine mind that most closely parallels the ego of the Meditations. Like the Divine mind, the Cartesian mind requires no medium, sensory or otherwise, to be activated. The ego, like the Divine mind, knows its essence directly. As opposed to the Aristotelian soul, the ego has no need of sensory or bodily organs to transmit images to the agent or passive intellect. Nor does the Cartesian ego require universal forms, as do Thomas’ angelic minds. Because no image is necessary to activate the Cartesian ego, it “does not ‘traverse,’ as do Thomas’ separate substances, the ontological distance from potentiality to actuality.” Nor is the Cartesian mind divided into the agent intellect and potential intellect. The Cartesian mind is always actual in the same way the Divine mind is, but in a finite, as opposed to an infinite sense. The ego is always, first and foremost, an act or intuition of existence, and is in act prior to any conscious mental act. The Cartesian mind, unlike the Aristotelian God that is thought thinking itself, is actualized before it thinks itself. One might ask what thought thinking itself was before it thought of itself. Finally, the Cartesian mind does not require a body (and therefore the external world) to be.
The nature of the ideas innate in the Cartesian mind (God, the ego, wax) are all encompassing, in the sense that the mind has an idea of all essences. In other words, the mind does not require the particulars of sense perception to grasp universal concepts. Logic, for instance, is not based on the particulars of sense, but on concepts reducible to mathematical or physical principles and properties. Cartesian man’s act of being— thinking— is not a bodily act. The self, or the mind, is not individuated by matter, whereas material objects are. The Cartesian mind knows the same universals as the Divine mind, but the difference is that the Cartesian mind is embodied, and thus subject to error:
..so long as I think only of God, and turn my whole attention to him, I can find no cause of error or falsity. But when I turn back to myself, I know by experience that I am prone to countless errors.
In terms of further limitation, the mind is created by God, as Descartes states in the Third Mediation; Cartesian man’s act of being is not an act of self-creation, but an intuition of the self and an understanding of the essential nature of all things (e.g., Descartes’ experiment with the wax in the Second Mediation). In this respect, Descartes’ proof for the existence of God from the principle of causality in the Third Meditation is the only way of measuring the powers of rationality and the contents of the mind that has a rational understanding of all things.
The approximate identity of the Cartesian mind with the Divine mind is further underscored by Descartes’ emphasis on the ease with which the existence of God is “thinkable.” To discover the existence of God, Descartes substitutes the chain of causes in the sensible order for the chain of causes in the order of ideas. That the existence of God, according to Descartes, is more self-evident than the existence of the sensible world contradicts the Aristotelian/Thomist conception of the intellectual soul, which apprehends its object via the simple class of objects that Aquinas refers to as “sensible by accident,” or objects which are intelligible in themselves. Thomas argues that man’s knowledge of the existence of God, deriving from the order of created things, points to the necessity of His existence as the first cause of the material world, and the requirement that there exist in the universe intellectual creatures that bear “a likeness to its source, according to its being and its nature, wherein it enjoys a certain perfection.”
In the Third Meditation, the necessity of the mind’s a priori knowledge of the existence of God is deduced from the infinite nature of God. Descartes argues that the rational mind possesses the idea of an infinite being; the rational mind is finite, hence the finite mind’s idea of an infinite being must have a source outside of itself. Because a finite mind cannot generate the idea of an infinite being, it stands to reason that God put the idea of Himself in the rational mind. There is no other means, Descartes argues, by which a finite mind could be in possession of the idea of an infinite being. Descartes maintains that,
…the mere fact that God created me is a very strong basis for believing that I am somehow made in his image and likeness, and that I perceive that likeness, which includes the idea of God, by the same faculty which enables me to perceive myself.
The proposition that the mind is made in God’s image and likeness rests upon the assumption that the mind possesses judgment, rationality, and will — in other words, those communicable attributes that God possesses infinitely and perfectly, and the human mind to a limited and finite degree. Because the meditator perceives both God and the ego through the same faculty (the understanding), what is predicated of God (infinity and perfection) is also predicated of the mind, but to a diminished degree of perfection. The intuitive assertion of the “cogito” is ego cogito, ego sum; je pense donc je suis; I think, therefore I am. The parallel of Descartes’ philosophical doctrine to God’s answer to Moses on Mount Sinai was probably not lost on him. After all, the title of his Le Monde de M. Descartes ou le traité de la lumière, too, was intended as a reference to the command of God Himself, on the first day of the world, “Let there be light!”
In the final analysis, the Cartesian mind is not identical to the Divine mind, but bears a similarity to it in the same respect that the mind’s idea of extension only bears a similarity to extended things. An analogous parallel can be found in the cognitive lacuna that divides Thomas’ Divine mind from his separate substances, the angels. We can formulate a tripartite ontological lacuna in Descartes’ distinction of the thinking thing as such, and extended things as such; second, his distinction between the mind’s ideas of extended things, and extended things as such; and third, his account of the mind’s idea of God, and God as such.
The rational mind is, as Descartes phrases it after Augustine, caught between “being and nothingness.” The lacuna between the mind’s ideas of essences and material objects existing in time and space is the same ontological lacuna that obtains between being and non-being. What commentators term the “similarity thesis” refers to the objects of sense experience bearing a similarity to the mind’s ideas of objects of perception; the two are not identical, and therefore not dependent on one another for their respective operations. The body is a mechanism that functions on the circulation of blood, performing all of the same movements even if there is no mind in it. Hence, the lacuna between the rational mind and the body-machine is identical to the lack of correspondence between being and non-being as such.
Like Thomas’ separate substances, the Cartesian mind is caused by the Divine mind, and reflects the Divine mind in an imperfect, finite way. The difference between the modes of being enjoyed by God, who possesses both an infinite will and mind, and the limited faculties and powers enjoyed by man is such that “no essence can belong univocally to both God and his creatures.” What can be predicated essentially of man depends, according to Descartes, on the rational clarity by which the truth is perceived by the mind. “No actions,” Descartes claims, “can be reckoned human unless they depend on reason.”
The distinction again applies in the case of the ontological lacuna between the rational mind and the Divine mind. What is predicated of the rational mind, such as the mind’s knowledge of the truth or falsity of ideas, cannot likewise be predicated of the Divine nature. The mind and will of God is free in the absolute sense, and beyond truth and falsity. Thus, the limitless will and power of God enjoys an indifference to the created and uncreated as such. God, considered as an infinite, perfect substance, determines the order of things to be such for no other reason than that He wills it to be so. In the Sixth Set of Replies Descartes states, “the way in which it [viz., the freedom of the will] exists in God is quite different from the way in which it exists in us.” Descartes’ admission that he could not demonstrate that God could not annihilate the soul stems from his conception of the absolute freedom of an infinite God.
God’s freedom derives from His absolute indifference, or in Descartes’ words, “it is impossible to imagine that anything is thought of in the divine intellect as good or true… prior to the decision of the divine will to make it so…there is no “priority of order, or nature, or… rationally determined reason [that] impelled him to choose one thing rather than another.” Lastly, the rational mind is distinguished from the Divine mind in the respect that the rational mind perceives concepts that are immutably true, while the Divine mind, the infinite, perfect, incomprehensible originator of all is omni potens, and above rationality. Rationality is by definition a property of finite creatures that observe rules and operate according to mechanistic laws. God’s essence, according to Descartes, is not identical to the universal laws of mechanics; God’s essence consists of a will of “inexhaustible power,” hence the “cause or reason why he requires no cause.”
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