Plato & Aristotle on the Intersection of Epistemology and the Philosophy of Mind

My research is centered around Plato’s Theaetetus and I begin by introducing, what I consider to be, the core concerns of the text. The bulk of the dialogue is dedicated to a refutation of the Protagorean relativist thesis that “Man is the Measure of all things, of those that are that they are and of those that are not that they are not.” (152a). The claim is a relativist one, according to Plato, because it says that every judgment that a person ever makes is necessarily true, and false judgment is impossible. In order for this claim to hold, the truth of the judgment has to be relativized to the individual speaker such that a given judgment is true only for them. The position is supported by a Heraclitean metaphysics, which contributes the claim that the features of objects are products of our experience of them, which makes them private to the one experiencing them. Overall, the position states that the judgments that we make are confined to describing our private worlds, to which we have access through perceptual experience. By positing epistemic equality for all, the position threatens the concept of knowledge but it also undermines the organization of our shared lives, as that depends on the idea of epistemic variation.

The greatest threat that the Protagorean position issues is to our self-conception as thinkers. The view is committed to the claim that it is not possible for our judgments to deviate from the contents of our perceptual experiences. This means that the contents of our judgments are determined by the world in much the same way that our sensations are determined by the world. Specifically, that judging is something that happens to us, like feeling cold by being cooled, and not something that we do self-consciously. For the Protagorean, our perceptual capacities are affected by the object and these affections are transformed into words and later expressed. These expressions, which necessarily reflect the affections caused by the perceived objects, are our judgments. The effect is that the Protagorean conception makes judgments akin to exclamations. But importantly, exclamations are not true or false, so if judgment is as Protagoras describes it, then the ruling out of falsehood comes at the cost of ruling out truth too. One of the projects I have been developing seeks to clarify the extent to which the Aristotelian conception of judgment that is presented in his work on the soul (De Anima) avoids the relativistic charge despite its bearing mechanistic features.

Insofar as judgment is explained as a causally determined event, it is not explained as an intelligent act carried out by a self-conscious subject who is in control of themselves. Not only are these two competing explanations, but the mechanistic one leaves no room for a subject’s self-consciousness to do any explanatory work, leaving it out of the account. The distinguishing feature of the self-consciousness conception is that it gives a teleological structure to the activity of judgment. Since the subject is responsible for putting together their own judgment, it falls to them to direct their activity, which opens up room for it to be done well or badly. The activity is subject to standards of correctness, which the judgment-maker is sensitive to and imposes upon oneself. Since judgments are the kinds of sayings that present the world, judging well means judging truly and judging badly judging falsely. Thus, the possibility of falsehood, the possibility of genuine truth, and the possibility of self-conscious subjects capable of methodical thinking all emerge together. Indeed, as the dialogue presents the matter, it is the introduction of a soul with a teleologically structured inherent activity that is responsible for the possibility of truth. An upshot of this position is that judgments that are true or false presuppose the psychic act of aiming at the truth. So, Protagorean relativism will be defeated, according to the Theaetetus, only if we exercise our characteristic self-conscious capacity to aim at the truth. A curious and under-examined (both by Plato and by scholars) feature of the Theaetetus’ discussion of the soul’s teleological activity is that it involves an orientation to the future. The other project I am developing seeks to understand this connection between purposefulness and the future.

There is reason to think that Aristotle’s account of the coming to be of judgment, as it is outlined in De Anima, lacks the truth-oriented teleological structure which, I have argued, Plato has identified as the condition for the possibility of judgment that is genuinely true or false. Two intimately linked aspects of Aristotle’s view betray the tendency towards assimilating judgments to exclamations: the mechanistic description of how perceptual judgment comes to be, which leaves no explanatory lacuna for truth-orientedness to fill; on the other, the fact that the resulting judgment, insofar as it might be said not to be the product of perception and imagination does not bear any characteristics that may clearly indicate that it is oriented to the truth rather than merely exclaimed. I will briefly discuss these two features in turn, before offering an Aristotelian solution from elsewhere in the corpus.

Aristotle sharply distinguishes perception and thinking, broadly construed, which leads to distinct accounts of perceptual cognition and discursive judgment. In fact, it is not clear that the former may be glossed as a kind of judgment at all, because the sort of falsehood that might attach to it is best construed as a kind of malfunction. Aristotle is explicit that perceptual capacities do not err as regards their proper sensibles (III.3), that is, colors for vision, sounds for hearing, etc., [1] but he admits that error is possible in cases of “common sensibles” (things like shape or motion, which are apprehensible by multiple sense modalities) or “incidental sensibles” (as in seeing Socrates as opposed to his color). Yet, none of these is a case of noetic synthesis, which he says is required for falsehood (III.6). Given that the perception of proper, common, and incidental sensibles all fall under the capacity for perception, as opposed to discursive synthesis, falsehood may only be possible either as a result of something going wrong in the material process of perception or as the veridical cognition of a false presentation. [2] The latter option is absurd but the former is equally unpromising, for it underscores that perceptual cognition is not the product of a capacity of a self-conscious subject but rather an event determined by factors entirely outside the subject’s control and understanding. As such, these perceptual cognitions cannot be true or false. While the capacity for perception may be said to be oriented towards an apt apprehension of reality, as determined by the nature of the species, this apprehension does not seem to bear the characteristics of representation [3] nor to distinguish between true cognition as opposed to some other desirable kind of cognition, such as optimal-for-survival. This option faces the further issue of how to bring together the strictly material products of sensation with the conceptual content that figures in acts of propositionally structured discursive judgment about the same perceptible facts.

This brings me to the second issue. Aristotle is explicit that human discursive judgment is not possible without the products of imagination, which is a faculty activated in perception and has the function of storing, as it were, perceptual content in the body, which can be used for other cognitive activities, including remembering, desiring, and judging. It is these imagination- contents, together with noetic content (what Aristotle calls ‘essences’) grasped by the intellect (nous) rather than perception, that come to be synthesized in judgment. Yet, neither of these contents is marked by an inherent orientation towards truth, that is, neither is the sort of thing that is essentially such as to be slotted into propositional forms for the sake of giving rise to a true judgment. [4] Since the contents themselves do not bestow truth-orientedness to the cognitions, the only other option [5] is to credit that which is responsible for the synthetic act itself, namely the intellect. Yet, problems lurk here too. Aristotle does not say that this synthetic act is oriented towards the truth or, more generally, that there is some aim guiding the synthesis. In fact, his focus on the intellect’s capacity to isolate essences from one another does not imply such an orientation because that characteristic noetic act is presented as a kind of intuition, much like perception, that is, as an act that either grasps or does not grasp its target rather than an act that succeeds at representing its target, whether truly or falsely. Finally, the thought that the noetic part of the soul imposes an orientedness to the deliverances of perception undermines the Aristotelian claim that the body is to the soul as tools are to an art and not to an artisan. [6] The solution to these issues, I take it, is to fit into the account of the human soul the category of rational capacities, which Aristotle discusses in Metaphysics IX.2 and 5. These are also conceived on the model of art but the emphasis there is on the fact that an art is inherently oriented towards an end (as health is for medicine), which introduces correctness conditions and requires the subject’s self-conscious apprehension of these conditions as normative standards for their conduct. [7]

In the argument for the soul’s formal orientation to the truth, it is curiously mentioned that the soul looks to the future (186b). In an earlier, very brief and schematic, argument, Socrates uses the notion of the future and the case of predictive judgments to mount a decisive (179b) blow against the relativist position. I offer an account of this argument that establishes that future- orientedness is a misnomer for the activity that is self-conscious about the normative standards that govern its own activity. Most commentators [8] take it that the case of predictions serves to circumscribe a set of cases in which falsehood gets a foothold, for the sake of undermining the overall position, while others suppose that the argument is merely ad hominem. [9] Pace the former, I argue that this has already been achieved at an earlier stage of the dialogue; pace the latter, I argue that Plato is interested in the future as such and considers the orientation towards it to be a crucial feature of knowledge.

According to my interpretation, the passage makes two points. The first is that all judgments, including those of present perception (which constitute the core Protagorean case and which Aristotle continues to view as infallible) have truth-conditions and may thereby be false. This point is made on the basis of an analogy to the case of predictions, which gain truth-conditions by being oriented towards capturing the future fact. The second point is that it is intrinsic to the knower, qua authoritative (178d) about the future compared to the layperson, that she has the capacity to make judgments that are sensitive to standards of correctness. The worry that the knower’s capacity to countenance normative standards renders her a seer or soothsayer (despite Socrates’ explicit denial, 179a) should be quelled by the considerations that within the kind (eidos) of the future belongs benefit (178a), which is in each case the end of a craft (e.g. health for medicine). Thus, contrary to figures like Isocrates, who claim that Plato’s understanding of virtue (and so, knowledge) absurdly requires foreknowledge of future events, [10] the Theaetetus suggests that the expert is one who knows how to bring about the ends of her craft and how to navigate the criteria and truth-conditions that are determined by the craft (e.g. recognize fever as such). In the end, Platonic expertise amounts to a capacity to keep oneself focused on the principles of the craft and make judgments through its perspective. [11]