Tag: Descartes

Consciousness, Personhood

There is a common modern view that aims to explain who I am in terms of my consciousness. Locke, who popularized his friend the Cambridge Platonist Ralph Cudworth’s coinage of the new English word “consciousness”, already seems to have thought this way. Historically, a gradual increase in emphasis on the immediate awareness central to the thought of Descartes and Locke can be traced through Plotinus, Augustine, Avicenna, and the Latin scholastics. The curious thing is that consciousness is commonly supposed to be both a sort of universal transparent medium of experience and the locus of our personal self. I don’t think it is either of these.

I want to question the claim that there is any universal transparent medium of experience. It seems to me that the multitude of forms of awareness we experience is rooted more concretely in particular “contents”, rather than in a medium that allegedly contains them. In Lockean terms, particular kinds of awareness would be built into particular “ideas”. Ideas would no longer be inert representations as they are for Locke, but would have an active aspect of their own. In Aristotelian terms, I think the primary locus of human awareness is in our “imaginings” (see Imagination, Emotion, Opinion).

Personhood, I want to say, is neither psychological nor metaphysical but rather primarily ethical in nature. Who we are comes not from our consciousness but from our character and what we do. With respect to character, this is almost a tautology, but that is kind of the point.

Character is not inborn but acquired. It is Aristotelian ethos as particularly manifested in individuals. Ethos begins as a social acquisition of culture, but everyone completes it for themselves through the detail of their ethical practice.

The Act of Thought

Volume 3 part 1 of Alain de Libera’s Archéologie du sujet carries subtitles translating to The Act of Thought for volume 3 overall, and The Double Revolution for part 1. The cast of major characters will include Averroes, Aquinas, and the Scottish philosopher of common sense Thomas Reid (1710-1796). This tome is packed with extremely interesting material. It also appears to me to intersect with the important work of Gwenaëlle Aubry on the historical transformation of Aristotelian potentiality and actuality into a neoplatonic notion of power and a more modern notion of action. At the time part 1 was published (2014), part 2 was supposed to be a few months away, and de Libera announced titles for volumes 4 through 7. Instead, he has since published three volumes of related lectures at the College de France.

“The philosophers pose all sorts of questions concerning thought. Who thinks? Am I the author of my thoughts? What is the place of thought? What is its theater or its scene? In what way are the thoughts that come from me or that I have mine? Am I the owner of my thought? In sum: is it necessary to say ‘I think’ with Descartes, or ‘it thinks’ with [Belgian new wave musician] Plastic Bertrand, [and philosophers like] Lichtenberg, Schelling, and Schlick? It seems natural to us to believe that the act of thinking takes place in us. ‘Takes place‘ says a lot. That which takes place is [emphasis added]. Being is having a place of being — in other words: it is having (a) reason for being. But what takes place also happens. What takes place in us happens in us, is produced, is effectuated, is accomplished in us. What takes places in us is in us, in whatever way that it has being. It certainly seems natural to believe that since the act of thinking takes place in us, it begins and is completed in us. In us, that is to say in our soul (if we are religious), in our spirit (if we know the French for Mind), or in some part of us (if we [participated in the May 1968 Paris uprising]).”

“There is nothing ‘natural’ in all this. All these beliefs are cultural, and historically constructed. They are assimilated philosophical theses, philosophemes neither proven as such nor a fortiori proven as historical constructs, philosophemes (learned theorems, technical injunctions, theoretical words of order) lived without justification as immediate givens of consciousness, as a flower of experience” (p. 13, my translation throughout).

De Libera refers to very strong assertions by Thomas Reid about the common-sense character of all this. Reid explicitly refers to the mind as a subject. It was philosophers, de Libera says, “who decided that this, or that which thinks, was the SUBJECT of an act, the act of thinking. It was philosophers who decided on this subjective basis that this ‘that’ or this ‘it’ could be known as the author or the actor. They did this partly against Aristotle, and partly in the name of Aristotle….”

“The philosophical construction accounts for a fact of experience: we sense ourselves as the principle, that is to say also as the beginning, the point of departure… of our actions, notably, and very particularly of our thought. But exactly in accounting for this fact, the philosopher encodes it, and never ceases throughout history to re-encode it, to complicate it, to invest in it and reinvest in it linguistically, conceptually, argumentatively.”

“‘Denomination’ is one of the keys of this code” (p. 15). “According to Reid, to say that an agent x acts on a thing y is to say that a power or force exercised by x produces or has a tendency to produce a change in y. What is particularly interesting for an archaeology of the subject-agent of thought is that this schema does not apply to perception” (p. 17).

According to Reid, when we perceive objects, the objects don’t act on the mind, and the mind doesn’t act on the objects. To be perceived is an external denomination. According to de Libera, in the language of the Latin scholastics, causal denomination finds its main application in the domain of action. An action denominates its agent causally, and not formally or extrinsically. On the other hand, extrinsic denomination applies perfectly to the ontological and noetic analysis of the object of thought.

For most of the scholastics, as for most modern people, the being-thought of a stone is real in the human, but is not real in the stone. But de Libera points out that the great Thomist Cajetan says about thought in the passive sense what Reid says about perception — both the stone and the thinker are only extrinsically denominated by the being-thought of the stone.

As de Libera points out, Averroes and his Latin followers have been understood as arguing that thinking is an extrinsic denomination of the human. “It requires a solid engagement with [Aristotle’s work on the soul] and its Greek, Arabic, Jewish, and Latin interpretive tradition to understand what this means” (p. 22).

Church councils in the 14th and 16th centuries upheld the opposing views of Aquinas as doctrinally correct. According to de Libera, this opened two paths, one leading to Descartes and the “Cartesian subject”, and the other leading to what he calls a Leibnizian notion of subject as the “thing underlying actions”. He says there is also a third path, leading from Averroes to Brentano, who reintroduced the scholastic notion of intentionality in the late 19th century. In this sense, he says the middle ages were more modern than we realize, and modernity is more medieval than we realize.

De Libera notes that Foucault ultimately derived his philosophical use of the word “archaeology” from Kant. Such archaeology is concerned with very Kantian “conditions of possibility”.

Taking the modern notion of “subject” at its point of emergence demands that we look back to the scholastic subjectum and “being in a subject” — not for the pleasure of returning to the middle ages, but in order to understand Descartes in context. It was not actually Descartes who was responsible for the transition from what Heidegger called “subjectity” (simply being a thing standing under something else) to the mental “subjectivity” of an ego.

Incidentally, de Libera points out one of the first uses of the word “subjective” in a modern sense in Martin Schoock, an early Dutch critic of Descartes who objected that Descartes reduced thought to something “subjective”. He quotes Schoock as saying “The reason Descartes brags about is not reason understood in a general sense, but in a subjective sense, that is to say the reason he can consider in himself” (p. 30).

Here I would note that in an interesting little meditation on Averroes called Je phantasme (“I imagine”), de Libera’s former student Jean-Baptiste Brenet points out that general Latin use of the verb cogitare referred primarily to operations of what in Aristotelian terms was called “inner sense”, as distinct from intelligere, which was the standard word for the “thinking” attributed to “intellect”.

(Inner sense is the closest Aristotelian analogue to what Locke more abstractly called “consciousness”. At least in the Arabic commentary tradition, it seems to involve several distinct faculties that all have what Aristotle and the scholastics following him called “imagination” as their common root. These are said to include what animals use in place of reason to make meaningful discriminations such as the nearness of danger, which is not actually given in external sense. Descartes’ own usage of cogito (first person singular of cogitare) basically covers all forms of awareness. It is a commonly repeated “Aristotelian” dictum that nothing comes to be in intellect without first coming to be in sense perception, but de Libera in an earlier volume pointed out that a more accurately Aristotelian version would be that nothing comes to be in intellect without some basis in imagination, and nothing comes to be in imagination without some basis in sense perception.)

Origins of a Subject-Agent

How did the modern equation of subjecthood and agency come to be? How did the notion of “I” or ego come to be substantialized? An extremely influential argument of Heidegger makes this an innovation of Descartes. Alain de Libera argues that this is too hasty, and that the groundwork for this identification was actually laid in the later middle ages. I’m continuing a high-level treatment of de Libera’s extremely important “archaeology of the subject“ (see also On a Philosophical Grammar).

Answering this question will involve an extended historical odyssey through complex interactions between Aristotelian and Augustinian views, and much more. De Libera sees Aquinas in his polemic against Averroes raising four interrelated questions of a more fundamental nature: Who thinks? What is the subject of thought? Who are we? What is man? The second of these seems to have been first asked by Averroes. The other three are largely attributable to Aquinas and his contemporaries, in their reactions to Averroes.

Several points of Aristotelian interpretation (What is substance? What is form? What is act? What is an efficient cause? What is the soul?) will be relevant to answering these, as will Augustine’s meditations on personhood and the nature of the Trinity. De Libera notes that John Locke — a major contributor to modern views on “the subject” — was deeply involved in debates on trinitarian theology. He also discusses Franz Brentano’s modern revival of the medieval notion of intentionality. The medieval version was closely bound up with a notion of “inexistence” or “existing in” of mental objects (forms separated from their matter) in the soul.

In the Categories, Aristotle gives substance the logical sense of something standing under something else. This influenced the Greek grammarians who formulated the notion of a grammatical subject. But in the Metaphysics, he treats this as only a starting point that is quickly superseded by an identification of substance with form or “what it was to have been” a thing, before moving into an account of substance as potentiality and actuality.

De Libera notes a historic division among readers of Aristotle’s treatise On the Soul between those who interpret the soul as an attribute of the body, and those who treat it as a substance in its own right. The latter position has different meanings, depending on whether substance is taken in the “standing under” sense or in the sense of form. De Libera will be particularly interested in the consequences of a further family of positions that make the non-obvious equation of human actions and passions with attributes of the soul.

He notes that “category” in Greek originally meant accusation, and relates this to Locke’s characterization of personhood as a “forensic” notion. We have here to do with subtle relations between attribution, inherence, and imputation with respect to actions and passions in relation to the soul. But what is an action? Must we explain an act in terms of a substantial subject’s power of efficient causation in a late scholastic sense that is far from Aristotle’s? (See also Expansive Agency; Brandomian Forgiveness.)

Wisdom and Responsibility

Among other works, the great early 20th century philosopher Edmund Husserl wrote his own Cartesian Meditations, an expanded version of lectures delivered in Paris in 1929. Husserl developed his own version of phenomenology, very different from Hegel’s, and his own version of transcendental subjectivity, very different from Kant’s. Throughout his career, he was concerned to criticize naive notions of objectivity. While disagreeing with a few of his fundamental principles, I enormously admire his nuanced development and intellectual honesty.

Husserl writes that “The aim of [Descartes’] Meditations is a complete reforming of philosophy into a science grounded on an absolute foundation” (Cartesian Meditations, p. 1). I think of philosophy as concerned with generalized, coherent interpretation of life and the world as an ongoing, never-finished project, rather than a completed rational “science”. But Husserl, with all his scruples about premature claims of objectivity, is famously provisional in most of his actual developments. As long as the ultimate “science” remains an aim and is not claimed as a present possession, we have not fallen into dogmatism. I think Husserl overall actually does better than Kant at avoiding overstated claims of “scientific” accomplishment.

According to Husserl, Descartes “gives rise to a philosophy turned toward the subject himself” (p. 2). I tend to worry more about illegitimate claims on behalf of a sovereign Subject than about premature claims to know about real objects, but both concerns are valid. “Philosophy — wisdom (sagesse) — is the philosopher’s quite personal affair. It must arise as his wisdom, as his self-acquired knowledge tending toward universality, a knowledge for which he can answer from the beginning, and at each step” (ibid).

The literal meaning of the Greek philosophia is “love of wisdom”. Some kind of wisdom, rather theoretical knowledge, was the main goal of ancient philosophy, from Plato and Aristotle through the Stoics, Epicureans, and Skeptics, all the way to the neoplatonists. An emphasis on wisdom as distinct from knowledge puts a “practical”, ultimately ethical dimension above all particular inquiries, whereas Latin scholastics focused on more technical debates about the truth of propositions, and early modern philosophy was permeated with ideals of pure science. I think it was really more the Kantian primacy of practical reason than the Cartesian cogito that initiated a partial turn back to the ethical concerns of the ancients. Some writers have suggested that claims for the revolutionary character of the cogito are more shaped by Kant’s interpretation and by the perception of Descartes as a precursor to Kant than by Descartes’ original.

Commentators have noted that ethical concerns are basically absent from Descartes’ Meditations. Kant and Husserl each in their own way reinfused broadly ethical concerns into Descartes’ preoccupations with the foundations of knowledge.

Husserl appeals to “the spirit that characterizes radicalness of philosophical self-responsibility” (p. 6). “Must not the demand for a philosophy aiming at the ultimate conceivable freedom from prejudice, shaping itself with actual autonomy according to ultimate evidences it has itself produced, and therefore absolutely self-responsible — must not this demand, instead of being excessive, be part of the fundamental sense of genuine philosophy?” (ibid).

This Husserlian appeal to autonomy, like Kant’s, ultimately still has to answer to the critiques of Hegel and Brandom (see In Itself, For Itself; Autonomy, Normativity; Self-Legislation?). Nonetheless, it is a high point in the development of the human spirit.

Flying Man?

Back in 2019, I included the following in a tangent near the end of a longer post:

“The thrust of the famous cogito ergo sum was already anticipated in Augustine’s Confessions. A more detailed version was developed by Avicenna, in an argument known… as the “flying man”. He proposed a thought experiment, considering someone in counterfactual absolute sensory deprivation from birth, with the intent of asking whether awareness could be completely independent of sensibility. He argued that the person in absolute sensory deprivation would still be aware of her own existence, due to a pure immediate reflexive awareness intrinsic to the soul and independent of the body. This kind of claim would have been accepted by Plotinus, but rejected by Aristotle or Hegel. Medieval Augustinians, however, enthusiastically adopted many of Avicenna’s ideas.” Peter Adamson, a scholar of Islamic philosophy, has a nice short article on this.

What Descartes Proved

The Latin subtitle of Descartes’ Meditations advertises that they not merely assert but demonstrate the existence of God and an immortal soul. However, as noted in the Cambridge Descartes Lexicon, neither the word “immortality” nor “immortal” even appears in the body of the text. Descartes does convincingly argue that even in the very act of doubting everything, it is apparent that something is going on — that there is awareness or “thinking”, even on the extreme assumption that everything it thinks is mistaken.

“What then did I formerly believe myself to be? Undoubtedly I thought myself to be a man. But what is a man? Shall I say a rational animal? No, for then I should have to inquire what is ‘animal’, what ‘rational’; and thus from one question I should be drawn on into several others yet more difficult. I have not, at present, the leisure for any such subtle inquiries. Instead I prefer to meditate on the thoughts which of themselves spring up in my mind” (Descartes’ Philosophical Writings, trans. Norman Kemp Smith, pp. 203-204).

Descartes argues that bodily phenomena are not clearly “me”, but that I cannot separate myself from my awareness. “Thinking? Here I find what does belong to me: it alone cannot be separated from me. I am, I exist. This is certain. How often? As often as I think” (p. 205).

He makes a subtle transition from arguments about the indubitable existence of some awareness to arguments about something that has the awareness.

“What is a thinking thing? It is a thing that doubts, understands, affirms, denies, wills, abstains from willing, that also can be aware of images and sensations” (p. 206). Elsewhere he also includes love and hate. Using contemporary vocabulary, Gueroult calls this a thinking subject (Gueroult, Descartes, p. 40), a word Descartes himself does not use in this context. Descartes identifies it with his own view of the soul. Though Descartes thinks it is separable from the body and the world, he treats it as a concrete “me”.

This concrete me-thing is supposed to have some very strong properties. Descartes claims it is a substance — apparently in the sense of something underlying — and that we can know something is a substance without knowing it as a substance. Secondly, “Interior to the Cogito, consciousness [French conscience, which predated Cudworth and Locke’s English word] and consciousness of consciousness are identical” (Gueroult, p. 99, my translation, brackets and emphasis added). Thirdly, the Cartesian soul is supposed to have “infinite” free will.

On my reading, the earlier transition from the indubitability of the existence of some concrete awareness — which I take to be genuinely irrefutable — to the assumption of a “thing” that has the awareness, is only valid if the “thing” is strictly identified with the awareness itself. But if the “thing” is identical with the awareness we started with, then the transition to calling it a substance is not justified. Conversely, if “thing” does have strong enough meaning to justify calling it a substance, the transition from thinking to a thinking thing was unjustified.

The identity of consciousness and consciousness of consciousness seems to be a completely unproven and unprovable assumption — one that I think Aristotle, Kant, Hegel, and Ricoeur each convincingly suggest we should oppose. Gueroult quotes Descartes in a letter making the weaker claim that (contrary to what Locke would assert a bit later) the soul is capable of thinking of many things at once. If we accept this, that would make a simultaneity of consciousness and consciousness of consciousness possible in particular cases, but it still falls far short of establishing their identity.

Like many voluntarists, Descartes makes a leap from the much weaker claim that we make real choices, to the ultra-strong claim that our power of choice is completely unconditioned, and that divine omnipotence exempts it from the natural order altogether.

He argues at length that an omnipotent God is the necessary foundation of the razor-thin subjective certainty he discovered by introspection. The arguments about God are introduced as follows: “Those [ideas] which represent substances are without doubt something more, and contain in themselves, so to speak, more objective reality (that is to say participate by representation in a higher degree of being or perfection) than those which represent only modes or accidents; and again, the idea by which I apprehend a supreme God, eternal, infinite, immutable, omniscient, omnipotent, and the creator of all things which are on addition to Himself, has certainly in it more objective reality than those ideas by which finite substances are represented.”

“Now it is manifest by the natural light that there must be at least as much reality in the efficient and total cause. For whence can the effect draw its reality if not from its cause? How could this cause communicate to it this reality if it did not itself have it? And hence it follows… that what is more perfect, i.e. contains more reality, cannot proceed from what is less perfect” (pp. 219-220).

“By the name God I mean a substance that is infinite, immutable, independent, all-knowing, all-powerful, and by which I myself and everything else, if any such things there be, have been created. All those attributes are so great and so eminent, that the more attentively I consider them the less does it seem possible that they can have proceeded from myself alone; and thus, in the light of all that has been said, we have no option save to conclude that God exists” (p. 224).

Out of nowhere, we suddenly have an unexplained appeal to a fully formed late-scholastic distinction between substance, mode, and accident, and other scholastic reasoning about the superiority of causes to their effects. The implicit claim seems to be that these very particular historical formulations are universally given in intellectual intuition.

Descartes’ subsequent argument is literally that God is the efficient and total cause of everything, therefore He exists. Need I point out that only an existing being could be an efficient and total cause in the first place (assuming there is such a thing as a total cause)? And that the argument is therefore patently circular? Though still debatable, Anselm’s ontological proof and the various arguments of Aquinas were much more persuasive than this.

Plotinus, Augustine, and Avicenna all anticipated Descartes’ strong sense of interiority. What was relatively new in the metaphysics of Descartes was his narrow point about the otherwise empty certainty that “awareness exists”, but even that was partially anticipated by Avicenna’s “flying man” argument.

Cartesian Metaphysics

For Descartes, according to Gueroult, “metaphysics” is the universal science or the system of science, and also a kind of introduction to more concrete studies. Here we are far from Aristotle and much closer, I think, to Duns Scotus. Without knowledge of God and oneself, Descartes says, it would never be possible to discover the principles of physics. Gueroult says that Descartes insists on an “incomprehensibility” of God that is neither unknowability nor irrationality but the “formal reason of the infinite” (Descartes selon l’order des raisons, p. 17). This again has a somewhat Scotist sound to my ear.

The infinitude of God puts God absolutely first, as the first truth that founds all others. Gueroult quotes Descartes saying, “It is a ‘blasphemy’ to say that the truth of something precedes God’s knowledge of it…, because the existence of God is the first and the most eternal of all the truths that can be, and the truth from which all the others proceed” (ibid; my translation).

Descartes says that God “freely creates” eternal truths. I have no idea what creation of eternal truths could even possibly mean, though such a notion seems to be at least implicit in the teaching of Duns Scotus. To be eternal is to have no before and after. Therefore, it seems to me, all eternal things must be co-eternal. This point of view accommodates part of Descartes’ thesis, insofar as if all eternal things are co-eternal, then an eternal truth would not “precede” God’s knowledge of it. In broadly neoplatonic terms, eternal truths could plausibly be regarded as aspects of the “nature” of God. I can also grasp the idea of truths following logically from the “nature” of God, but I suspect Descartes would either follow Scotus in arguing that God’s infinite power is not a “nature”, or follow Aquinas in arguing that God is pure existence and has no other “nature”. I don’t see how anything more specific can directly follow from either infinite power or pure existence.

For Descartes, though, God’s omnipotence “excludes the possibility of error” and “alone founds the objective validity of my intellectual faculty” (ibid). Descartes aims at “a total system of certain knowledge, at the same time metaphysical and scientific, … entirely immanent to mathematical certitude enveloped in the clear and distinct intellect, … in its requirement of absolute rigor. This totality of the system is in no way that of an encyclopedia of material knowledge effectively acquired, but the fundamental unity of the first principles from which follow all possible certain knowledge” (p. 18). Descartes’ doctrine is for him “a single block of certainty” (p. 19) that would be falsified by adding or removing any detail. All this seems way too strong to me.

Gueroult points out that Descartes wants to contrast an “order of reasons” with an “order of material”, as being more principled. However, unlike geometry, the total system of metaphysical reasoning for Descartes has “psychological” as well as logical requirements. Gueroult says it is for this reason that the Meditations best represent Descartes’ paradigm of rigorous analytic demonstration.

Granted that there is a clear “psychological” aspect to the Meditations, at this point I’m unsure what it means to relate that to the claimed rigor of the system. Moreover, adding a “psychological” dimension to what was said before about mathematical reasoning affects the very meaning of the claim of rigor. I think I understand what mathematical rigor is. I do not understand what “psychological” rigor would be in this context, but I suspect it may be wrapped up with what I would call extraordinary presumptions of absolute self-transparency and immediate reflexivity.

Gueroult on Descartes

Having been greatly impressed by Martial Gueroult’s two extant volumes on Spinoza’s Ethics, I wanted to challenge myself to get some sense of the detail of his magisterial Descartes selon l’order des raisons (1968). Sometimes called a “structuralist” in the history of philosophy, Gueroult systematically developed the fine grain of argument in Spinoza’s demonstrations, and here he does the same for Descartes’ Meditations.

Beginning with a distinction between understanding and explanation, Gueroult announces his intention to subordinate the former to the latter (p. 9). Here “understanding” is a sort of intuitive or imaginative grasp of the whole, whereas “explanation” develops the details in their interrelation. I am reminded of Paul Ricoeur’s great theme of the value of the “long detour”.

Gueroult says Descartes viewed “isolated thoughts” with a sort of horror. This is already interesting. I have long puzzled over Brandom’s treatment of Descartes as a proto-inferentialist, when Descartes has seemed to me on the contrary like an arch-representationalist who plucked “truths” out of thin air. Both Gueroult and Brandom take Descartes’ “method” very seriously. Brandom’s work previously set me on a path that led me to radically change my views of Kant and Hegel. Perhaps I’ll have to revise or modulate some of my judgments of Descartes as well.

For Gueroult, it is objective structures of argument that distinguish philosophy from poetry, spiritual or mystical elevation, general scientific theory, or mere metaphysical opinions. He says that even while “excommunicating” the history of philosophy, Descartes nonetheless formulated a good principle of reading, rejecting eclectic tendencies to pull out this or that idea from a great author, in favor of a systematic approach. Descartes is quoted saying the “precious fruit” must come from “the entire body of the work” (p. 11). This is an important complement to his one-sided insistence elsewhere on beginning with what is simple. However, Descartes is also quoted insisting that all conflicts of interpretation are due to shallow eclecticism and deficiency of method, and that wherever there is such a conflict, one side must certainly be wrong (pp. 13-14).

This insistence on univocal interpretation is one of my big issues with Descartes. It works well for things like geometry, but much less well for sorting out arguments about power or potentiality, for instance. Pushing univocal interpretation as far as it can go can be a very valuable exercise, but as soon as we leave pure mathematics, it also shows its limits. I think that while mathematical necessity can be understood as something we “ought” to recognize for a multitude of reasons, sound ethical judgment must in principle reach beyond what can be expressed with certainty by formal equations. Much as I admire a good mathematical development, I therefore think ethics is more fundamental for us humans than mathematics, and philosophy is more ethical than mathematical.

According to Gueroult, the seminal idea guiding all of Descartes’ work is that human knowledge has unavoidable limits due to the limits of thought, but within those limits it is capable of perfect certainty (p. 15). For Descartes, we do not know thought by things, but we know things by thought. As a matter of principle, we should doubt everything that does not come from the certainty of thought. We are thus offered a stark division between that which is supposed to be certain beyond question, and that which is vain and useless. I think this results both in a treatment of too many things as certain, and in a premature dismissal of aspects of human reality that are uncertain, but nonetheless have real value.

I agree that mathematical reasoning is capable of (hypothetical) certainty, but I contend that we humans live mainly on middle ground that is neither certainty nor mere vanity.

Descartes Revisited

Descartes is among my least favorite of those conventionally termed great philosophers. My treatment to date has been mainly limited to a few dismissive remarks. Here I’d like to add a few “historiographical” points of demarcation.

Insofar as there is general consensus among scholars, Descartes (1598-1650) first and foremost has claim to fame as a very influential promoter of something recognizably close to modern scientific method. He is often credited with the invention of analytic geometry, based on an early recognition of the systematic isomorphism between geometry and algebra. Galileo (1564-1642) had already taken up an approach to natural science based on mathematical analysis, which Descartes enthusiastically adopted. Descartes particularly promoted a methodology based on clear and distinct ideas, which he held to give certain knowledge. He advocated an orderly progression from the simple to the complex.

On a broad social level, Descartes is remembered for promoting the independence of scientific investigation, particularly from the doctrinal concerns of the Catholic Church. But he was also a religious thinker. While confessing in a private letter that he did not literally believe various details of received scripture, he was very engaged with proofs of the existence of God.

Numerous scholars have pointed out that outside the domains of mathematics and natural science, Descartes in many ways remained close to the Latin scholasticism of which he has been commonly regarded as the slayer. In Descartes and the Modern Mind (1952), for example, Albert Balz argued at length that the thought of Thomas Aquinas was an essential precursor to Descartes. I note that Augustine had already emphasized the importance of the interpretive role of reason, even in matters of faith. On Aquinas’ account, God gives us not only revelation, but also the natural light of reason. In Summa Contra Gentiles, Aquinas addressed questions of philosophy and theology entirely from the point of view of that “natural light”, while aiming to show that the natural light of reason independently leads to many of same truths he attributed to revelation. Descartes makes great use of a similar concept of the natural light of reason.

Both Descartes and Aquinas thought the natural light of reason, properly understood, gives us truths, full stop. I think it gives us invaluable criteria for judgment and interpretation, while always in principle leaving room for discussion about what conclusions should be drawn. I also think the “natural light” itself comes to us in degrees, and is never a simple or unproblematic possession.

A different strand of Latin scholastic thought tended to claim that all human knowledge originates in sensible images, while attributing such a view to Aristotle. (I think this is overly strong, and that Aristotle only meant to defend the pragmatic value of sensation against Platonic skepticism about all deliverances of sense.) Descartes famously argued that sensible images are not the only source of knowledge, and I think that is true, as far as it goes.

Here is where Descartes’ theses about clear and distinct ideas come into play. A methodological discipline based on examining whether our ideas are clear and distinct is an important source of human knowledge. Again, this much I can agree with, but I think clarity and distinctness are relative criteria and not absolutes. As relative criteria, they have been implicitly employed by most if not all serious thinkers. I take such evaluations to have been a major implicit concern of Platonic and Aristotelian dialectic, which in part aims to discern meanings that are more clear and distinct.

Descartes effectively claimed that clarity and distinctness are absolute, decidable properties of ideas. One of the broadly scholastic views he sharply criticized was that our best knowledge of sensible things is only “probable”. Descartes claimed that the results of his methodological analyses were certain, in the same way that mathematical conclusions follow with certainty from their premises. This goes well beyond the claim that there is practical value in such methodology.

Building on arguments of Augustine and Avicenna, he also famously gave great importance to the claim that immediate contents of the mind give evidence of unconditional certainty of the abstract existence of something. The very possibility that I could be deceived implies the abstract existence of an abstract something that could be deceived. Further, if something in any way appears to me to be such and such — even if I am wrong about all the details — independent of all the details, the barest fact of the appearance implies that some appearance generically “exists”.

The “I” that is in this way proven to exist and the appearance that is proven to exist are both extreme abstractions. Even Descartes did not claim that either of these existences by itself gives us any further knowledge. From this basis alone, I could still be entirely mistaken about the kind of being that I am, and about every detail of what appears to me to be the case. In spite of the famous Cartesian doubt, Descartes actually wanted to makes strong claims of certainty and to refute skepticism. Many readers have concluded, though, that he opened the door for a new, more global form of skepticism, because what he clearly establishes as certain seems so utterly lacking in content.

I would hasten to add that unreasonable, excessive skepticism about human knowledge is best refuted by successful achievements of goals in real-life situations. Only a hypocrite could claim to live in the world with no well-founded beliefs whatsoever. The ancient Skeptics were only “skeptical” about theoretical accounts of things, not about practical concerns of everyday life.

By setting the bar too high and aiming at absolute certainty, Descartes actually opened the door for more radically subjectivist views that no one in the ancient world would have taken seriously (and not just because ancient people were naive). At the same time, he was very impatient with “dialectic”, and tended to foreshorten discussions of meaning and interpretation, in favor of claims that certain contents are unequivocally clear and distinct. Thus the ultimate result of his thought oscillates unstably between extremes of “Cartesian” skepticism and dogmatism.

Another point on which Descartes has been very influential is his strong representationalism. For Descartes, strictly speaking we never have practical knowledge of things in the world, only knowledge about contents of our mental representations, insofar as they are clear and distinct. In particular, we only know bodies through our mental representations of them. Rather than consisting in an interpretive stance of a situated being in the world, the Cartesian cogito achieves its purely subjective certainty in a way that is supposed to be peculiarly “outside” the real world altogether.

Unlike the representationalism of Locke, which is grounded in a kind of empirical psychology, that of Descartes is closely bound up with an ontological mind/world dualism more radical than anything Plotinus, Augustine, or Avicenna ever contemplated. For Plotinus, Augustine, and Avicenna, the soul was a very special kind of “something” existing in the real world, even if for Plotinus and Augustine it was not a “subject” in the sense of something underlying something else. For Locke — the other great early modern promoter of representationalism — our mental worlds are ultimately contained within the natural world. For Descartes, there is the world and there is the soul, and never the twain shall meet. The soul has its own mental world where it seems to relate directly only to God, and human knowledge occurs only in that mental world.

It is due to this unprecedentedly radical mind/world dualism of Descartes, I think, that virtually no one — even among his admirers — wants to uphold his metaphysics. This is an extreme example of what Hegel called “alienation”.