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”.

“Western Metaphysics”?

“Metaphysics” has historically had numerous senses, mostly rather far from the way I read the original Aristotelian context. Neoplatonic commentators and later giants like Avicenna, Aquinas, and Scotus already radically reconfigured its meaning, long before the changes associated with early modernity. Authors like Heidegger and Derrida have famously made sweeping indictments of the whole of “Western metaphysics”, based on overly homogeneous and continuist interpretations of the history of philosophy. More broadly, Plato and Aristotle are far too often blamed for views they never held. Even the medieval Latin tradition was far more diverse and interesting than common stereotypes would allow.

Receptive Power?

The later neoplatonists developed a subtle and somewhat paradoxical notion of passive or receptive power. I call it paradoxical because “passive power” almost seems like an oxymoron. In modern terms, it is hard to see how something purely passive could meaningfully contribute to an effect, or even be called a “power”. But in a neoplatonic context, active and passive powers function as correlative terms that collaborate — albeit asymmetrically — to produce effects. When a “patient” is properly prepared, an appropriate “agent” power is supposed to spontaneously come to dwell within it.

All the change is on the side of the patient, whereas what is called “agency” in neoplatonism belongs on the side of the eternal and unchanging. Exactly how a patient in time comes to be properly prepared to be receptive to an eternal agent when it was not before is admittedly rather obscure.

In his late polemics against Pelagius, Augustine treated the agency of grace as residing entirely on the side of the eternal, even going to the extreme of denying that grace in any way depends on the merit or innocence of the recipient. His point seems to have been that grace does not depend on any kind of self-will, no matter how virtuous or innocent it may be — that it is always only received as a gift.

However obscure the neoplatonic notion of the preparation of patients may seem, in the context of a problematic like that of late Augustine, the attribution of effective reality to passive powers suggests a way out of the impasse we are left with if we consider only grace and self-will. Merit or innocence could be considered as configurations of such “passive powers”.

Proclus’ Elements

The later neoplatonist Proclus (412-485 CE) was head of the Platonic Academy in Athens, at a time when the Athenian Academy was somewhat notorious as the intellectual center of resistance to the spread of Christianity in the Roman Empire. Nonetheless, his work had a profound influence on the Arabic, Byzantine, and Latin traditions. He is usually cited as the main philosophical influence on the early Christian theologian pseudo-Dionysius, who was taken very seriously by Albert the Great and Thomas Aquinas.

Proclus wrote extensive commentaries on Plato, as well as an influential commentary on book 1 of Euclid’s Elements of Geometry. Hegel called him the greatest dialectician of antiquity. Though I think Hegel by his own principles really should have given that title to Aristotle, Hegel was right to recognize Proclus as important.

Aquinas is credited with recognizing that the Latin Book of Causes — a translation of the Arabic Discourse on the Pure Good — was mostly derived from Proclus’ Elements of Theology. Aquinas treated Proclus himself with considerable respect. Dietrich of Freiberg made significant use of his work, and his student Berthold of Moosburg wrote a very long commentary interpreting the Elements of Theology in Christian terms. The Renaissance theologian Nicolas of Cusa and the maverick Giordano Bruno were much inspired by Proclus.

Along with Spinoza’s Ethics, Proclus’ Elements shares the peculiar distinction of being written in a style visibly influenced by Euclid’s Elements. Euclid’s work has often been cited as a sort of paradigm of demonstrative reasoning. Though Proclus, unlike Spinoza, did not work from explicit definitions and postulates and used a looser style of demonstration, his Elements consists of theorems and a sort of demonstrations.

Proclus defends the neoplatonic idea of a One that transcends being, but as Gwenaëlle Aubry and Laurent Lavaud point out in the introduction to the French collection Relire les Éléments de théologie de Proclus (2021), perhaps his most influential idea is that of a very strong continuity from the highest principles to the most mundane effects, which has been read as a strong assertion of immanence as well as transcendence. He is an important source for all the later theological traditions that want to argue for simultaneous immanence and transcendence.

Proclus very explicitly crystallizes what I have called the generalized “unmoved mover” model of causality in Plotinus. For Proclus, “higher” and “lower” causes cooperate in the constitution of worldly things, but the higher cause is always more of a cause than the lower cause. At the same time, he rejects Plotinus’ identification of matter with evil, while emphasizing all of Plotinus’ more positive affirmations of the goodness of manifestation and the beauty of the cosmos.

In a separate treatise On Providence, he develops a sort of epistemic analogue to the generalized unmoved mover theory. “Providence” (pronoia — literally, “forethought”) is a knowledge-like thing that is superior to knowledge in that it is supposed to be eternal and unextended, and to involve no separation of what we might call subject and object. Proclus develops a subtle and suggestive account of something metaphorically like implicit, unextended “seeds” of forms within the overflowing of the One that transcends all extended form. While the One does not “know” worldly things, it “pre-knows” their unextended “seeds”, within something like what Schelling later paradoxically called the identity of identity and nonidentity.

In the Elements, Proclus argues for an interdependence of being, life, and intellect. While one obvious reading of this would emphasize a foundational role of spiritual beings in Proclus’ metaphysics, I am intrigued that it can also be interpreted as a somewhat “deflationary” account of being, closer to Aristotle, and far removed from later notions of pure abstract existence. We can’t begin to have an account of being, without also having an account of life and intellect. With his endorsement of a One beyond “being”, Proclus had no need for a commitment to a notion of pure “being”.

What Would Kant Say?

Kant famously put strictures on metaphysical speculation. Sometimes it sounded as if he intended to abolish metaphysics altogether, but I think his actual intent was a reform. What would he say about my recent dwelling on medieval debates about omnipotence? Perhaps the most obvious answer is that these all involve unknowable claims. But this might be proceeding too hastily. It was actually a tangent in a post on Kant’s notion of moral faith that got me thinking again about the first volume of Gwenaëlle Aubry’s “archaeology”, which led to my discovery of her second volume.

Aubry suggests that for Peter Abelard, actual good ethics are the most important thing in religion, more important than professing adherence to revelation. I think Kant would have been profoundly sympathetic to the broad spirit of this. Abelard seems to have held that ethical reason and revelation, properly understood, teach us the very same lessons. His faith was a moral faith, not the kind that claims to be a superior knowledge. Granted that saying is a special kind of doing and that what we say in life has a deep ethical importance of its own, it is still true that what we actually do in the general sense counts for more than what we say or profess.

Effective vs “Driving”

Modern thinking about causality remains haunted by the figure of “driving” causes on the model of billiard ball impacts, even though the use of sophisticated statistical methods in contemporary science already suggests the obsolescence of that model. I have characterized ordinary Aristotelian actuality as what is effectively operative in a process. This more general “pragmatist” notion of determination pays much more attention, e.g., to the role of the forms of things in shaping processes, but it also subsumes everything that was discussed on the narrower “driving cause” model.

Within the later tradition, the grounds for the early modern reduction of causality to an impact-modeled “driving” sense were laid by scholastic redefinition of Aristotelian efficient causality in terms of activity, and its simultaneous elevation above final and formal causes. I think that for Aristotle, the defining characteristic of an efficient cause is that it is a means by which an end is actualized.

The complete means by which an end is actualized undoubtedly involve activity, but in the example of building a house, for Aristotle it is the art of building that is the pre-eminent efficient cause of the actualized house — the pre-eminent means by which the building of the house is accomplished, even though there are many other contributing means and other causes. But the art of building is not itself an activity. This tells us that activity is not the defining characteristic of an efficient cause. It also brings the notion of efficient cause closer to those of final and formal cause. Taking into account the close relationship of Aristotelian form and matter, it turns out that all four of Aristotle’s causes are integrally related to one another.

I think that for Aristotle, activity is more a practical notion associated with broadly ethical doing, than a basis for theoretical explanation of events and properties. In Aristotle, activity is something inquired about. It does not play the role of an unexplained explainer. (See also Agency; Efficient Cause; Efficient Cause, Again.)

Potentiality and Ends

Perfection for Aristotle is an attractor and not a driver. To be an unmoved mover and to be an efficient cause in the “driving” way this was commonly interpreted in the later tradition are mutually exclusive. Pure act does not act in the normal sense of the word. I am reminded of Lao Tzu, that other great minimalist teacher of unmoved moving.

Plotinus and the later neoplatonic schools reworked the notion of unmoved moving, from Aristotle’s modest notion of the attraction of potentialities to the good, to a principle of overflowing, superabundant positive power that spontaneously generates beings and effects, as a necessary consequence of its very superabundance. Aristotle’s “first cause” affects everything, but only through the collaboration of secondary causes. Though developing nuanced accounts of the grand cycle of procession from the One and ultimate return, the neoplatonists tended to reduce secondary causes to mere effects of the One.

Authors like Aquinas engaged in a tricky balancing act, wanting to assert the supremacy of God while simultaneously recognizing the ethical and epistemological value of Aristotle’s emphasis on the reality of secondary causes. But according to Gwenaëlle Aubry, the theological voluntarism of Duns Scotus and others annulled what I take to be that good Aristotelian concern of Aquinas, completely subordinating nature, truth, and the good to the arbitrary will of God.

This whole historical discussion is greatly complicated by the very different ways in which the same key terms have been interpreted. For example, it makes a great difference whether we consider the art of building or the hammer’s blow to be a better model of the efficient cause. The art of building could be a sort of derived unmoved mover, but the hammer’s blow is a moved mover.

Previously, I have emphasized an interpretation of potentiality in terms of Brandom’s talk about robust counterfactual conditions on the one hand, and a loosely structuralist notion of structure on the other. I read Hegel as recognizing the essential role of this kind of potentiality in any formation of a determinate view of things.

This may sound remote from Aubry’s emphasis on potentiality as a tendency to be attracted by an end, but there is actually a deep connection. Hegel emphasizes the role of potentiality in determination, whereas Aubry emphasizes the role of potentiality as contingency. But Brandom’s counterfactual conditions (an interpretation of Hegelian potentiality) just are contingencies; they are not univocally determined to occur. From the ground up, a kind of pluralism of multiple concrete possibilities is built into the determination of determination.

As Leibniz said, all necessity is of a hypothetical, if-then form. As Kant and Hegel also reminded us, judgments of determination always involve interpretation, and ultimately have a normative form. Brandom makes a similar Kantian point that causality in the modern sense is a product of judgments and inference. These are far from arbitrary; they are subject to a kind of objectivity grounded in counterfactual robustness and mutual recognition. But that objectivity is itself ultimately a normative concept. As Abelard said, the good comes first. (See also Form as Value; Aristotelian Causes.)

Aquinas and Scotus on Power

Gwenaëlle Aubry’s Genèse du dieu souverain (Genesis of the Sovereign God) concludes with chapters on Aquinas and Duns Scotus. She finds that Aquinas systematically substitutes power and action for Aristotle’s less familiar and more subtle ends-oriented concepts of potentiality and act. Aquinas then distinguishes between active power and receptive or passive power, neither of which has much to do with Aristotelian potentiality.

For Aristotle, Aubry says, potentiality is an indwelling tendency of a being to be attracted toward an end. Pure act is the realization of an end (and, I would add, not itself a movement but an unmoved mover that is an attractor). For Aquinas, the receptive power of beings is the power to receive being from God. Pure act is equated with God’s creation from nothing. Aquinas strongly associates being with power; the power of God, pure Being, pure Existence, is for him an active and efficient cause, not an unmoved attractor. On my reading of Aristotle, it is only the less-than-pure acts of moved movers that are active and efficient causes; the “first” cause is an end that attracts beings.

Duns Scotus, according to Aubry, seems to have originated the modern notion of purely logical possibility. For Scotus, anything at all that is noncontradictory is possible, whereas Aristotle considered possibility more pragmatically, in relation to real-world conditions.

Scotus held that the order of the world is radically contingent, able to be reshaped by God’s will. According to Aubry, he explicitly speaks of God’s arbitrary choice, and attributes a power of arbitrary choice to the human will as well. For Aristotle, the source of contingency in the world is the potentialities of things. For Scotus, it is the absolute power of God.

Whereas Bonaventure, Aquinas, and the 14th century pope John XXII treated the “absolute” power of God as only logically distinct from the “ordained” power associated with the order of the world as we know it, and as not actually separately exercised, Scotus insisted that the absolute power of God is actually exercised. He identified the absolute power of God with a kind of pure fact, and insisted that God from eternity could choose to change the order of the world. (I’m inclined to think Abelard was right, and choice is incompatible with eternity.)

God’s choice for Scotus has no reason beyond itself. Scotus explicitly rejects the passage from Plato quoted by Abelard that everything that is has a cause or reason. Aubry says that for Scotus, the good is only good because God wills it so. This is the exact opposite of the argument of Plato, Abelard, and Leibniz that goodness comes first.

Scotus strongly emphasizes the infinity of God in contrast to the finitude of creatures; infinity for Scotus is God’s most important attribute. Moreover, God’s infinite power acts immediately in the world. This reminds me of the extreme positions on omnipotence articulated by Philo and al-Ghazali. According to Aubry, Scotus also says that a worldly prince enjoys a similar absolute power.

In passing, Aubry notes that Descartes — also a voluntarist — held that God creates eternal truths. This seems to be a somewhat Scotist position. (See also Aubry on Aristotle; Leibniz on Justice vs Power; Power of the One?; Disambiguating “Power”; Not Power and Action; Nature and Justice in Augustine; Peter Abelard; 1277; Being and Essence; Being and Representation.)

Being and Representation

In L’Être et représentation (1999), Olivier Boulnois documents the emergence of “metaphysics” in its distinctively non-Aristotelian modern sense among various 13th century authors, including Roger Bacon, Henry of Ghent, and Siger of Brabant, leading to its decisive formulation by the Franciscan theologian John Duns Scotus in the 14th century. Avicenna had already claimed that metaphysics is about “being in general”, whereas Aristotle himself had emphasized that “being is said in many ways”, which implies that there is no “being in general”.

Boulnois suggests that the 13th century authors just mentioned paved the way for Scotus’ innovations by already treating being as a concept. We are so used to that, that it is hard for us to grasp what Aristotle means in suggesting that “being in general” is not a proper concept at all.

Scotus argued against Aristotle that there is a unifying, logically minimal criterion of being, and it is representability. To be representable is to be “not nothing”. Unicorns and other imaginary creatures are representable, whereas Aristotle would not have called them beings. Scotus’ concept of representation seems to be purely logical; to have a representation of something is not necessarily to have understanding of it. For Scotus, God and creatures are equally representable, even though creatures, as finite, can be properly understood by the human mind and God, as infinite, cannot. Whereas Aristotle never speaks of an infinite being — only of a perfect one — Scotus’ generic concept of being is very explicitly indifferent to distinctions between finite and infinite.

It is one thing to acknowledge representation as a logical concept among others, and quite another to give it the kind of special first place status that Scotus does in his ontology, and that Locke does in his epistemology.

Boulnois says it is with Scotus that metaphysics became linked to what Kant later called ontotheology. While separating metaphysics as the account of being from theology as the separate account of God, Scotus also made God indifferently one of the objects of metaphysics, along with all the other beings. The combination of these changes actually brought metaphysics closer to revealed theology, and helped it to be perceived as the safe handmaiden of the later Latin tradition, rather than as independent philosophical theology that some found threatening.

If one speaks of a subject of representation, it could be — in a sense of “subject” closer to that of Aristotle — that in which something stands for something, or it could be — in a modern sense — the one who represents. “In the context of representation, the soul is not the content of its thought, but rather has a representation, distinct from itself” (Boulnois, op. cit., p. 152, my translation).

It seems that for both Scotus and Locke, the mind has representations. The soul in Aristotle is thoughts and feelings and capabilities, not something standing behind them. (See also Repraesentatio; Ontology; Being, Existence; Being and Representation Revisited.)