Alexander of Aphrodisias picks up Aristotle’s insufficient treatment of simultaneous perception and develops an adequate solution for the problem, thereby offering an account of the unity of perceptual consciousness—the single mental activity of a single subject with complex content. I show the adequacy of the solution by using as criteria the requirements that have been identified by Aristotle and approved (and explained) by Alexander. I analyze Alexander’s solution in two turns. First, with respect to heterogeneous perceptibles, Alexander adopts and reformulates (...) Aristotle’s metaphorical account invoking the analogy with a point. Second, with respect to homogeneous opposites, accordingly, perception is judgement, but it involves physical changes in diverse parts of the primary sense-organ. By this account Alexander resolves the issue of the unity of the subject on the level of the capacity of the soul, and coordinates the complexity of content with the complexity on the physical level. In addition to being adequate, the solution is faithful to Aristotle. I suggest that the interpretative decisions Alexander makes (the clarification of the analogy; the reference he finds to the analogy; the two components of the solution, judgement and parts of the organ) form an ingenious extension of Aristotle’s treatment. Interestingly, even though many elements in Alexander’s interpretation are taken up by modern commentators, no one has followed it in its entirety, nor even treated it in its own right. (shrink)

In this paper, I examine several key issues relating to the definition of knowledge as perception in the first part of Plato's Theaetetus. I begin by explaining the workings of the ‘secret doctrine’ of perception, which is introduced in order to support the idea that perception is incorrigible, and then turn to examine the two refutations of the definition of knowledge as perception which appear at the end of the first part of the Theaetetus. I shall present and explain distinct (...) lines of interpretation pertaining to these passages and explore the consequences they attempt to draw regarding Plato's views on the perceptual world, the nature of perception and how these bear on his conception of knowledge. (shrink)

On the face of it, Plato's treatment of aisthesis is decidedly ambiguous. Sometimes he treats aisthesis as a faculty which, though distinct from all rational capacities, is nonetheless capable of forming judgments such as ‘This stick is bent’ or ‘The same thing is hard and soft’. In the Theaetetus, however, he appears to separate aisthesis from judgment, isolating the former from all prepositional, identificatory and recognitional capacities. The dilemma is easily expressed: Is perception a judgmental or cognitive capacity, or is (...) it a non-judgmental, non-cognitive capacity? If the former, how does perception differ from belief? If the latter, is perception a faculty of the rational or irrational soul? Not surprisingly, the topic has received much scrutiny over the years. And equally unsurprisingly, the debate has turned as much on what it means for a capacity to be judgmental, cognitive, non-judgmental or non-cognitive, as on whether Plato says that it is of either kind. (shrink)

On the face of it, Plato's treatment of aisthesis is decidedly ambiguous. Sometimes he treats aisthesis as a faculty which, though distinct from all rational capacities, is nonetheless capable of forming judgments such as ‘This stick is bent’ or ‘The same thing is hard and soft’. In the Theaetetus, however, he appears to separate aisthesis from judgment, isolating the former from all prepositional, identificatory and recognitional capacities. The dilemma is easily expressed: Is perception a judgmental or cognitive capacity, or is (...) it a non-judgmental, non-cognitive capacity? If the former, how does perception differ from belief? If the latter, is perception a faculty of the rational or irrational soul? Not surprisingly, the topic has received much scrutiny over the years. And equally unsurprisingly, the debate has turned as much on what it means for a capacity to be judgmental, cognitive, non-judgmental or non-cognitive, as on whether Plato says that it is of either kind. (shrink)

For Plato, the crucial function of human cognition is to grasp truths. Explaining how we are able to do this is fundamental to understanding our cognitive powers. Plato addresses this topic from several different angles. In the Cratylus and Theaetetus, he attempts to identify the elemental cognitions that are the foundations of language and knowledge. He considers several candidates for this role, most notably, perception and simple meaning-bearing concepts. In the first section, we will look at Plato’s worries about semantic (...) instability and its epistemic consequences. The central role of basic cognitions in Plato’s account of knowledge in the Theaetetus will be explored in the second section. In the final section, the relevance of Plato’s conception of cognition to modern discussions in the philosophy of language and epistemology will be noted. (shrink)

In thesophist (263e10–264b4), Plato distinguishes between two kinds of belief. On the one hand, there is a kind of belief that occurs “according to thinking” (κατὰ διάνοιαν), being “the completion of thinking” (διανοίας ἀποτελεύτησις). This kind is called ‘doxa.’ On the other hand, there is another kind of belief that occurs “through sense perception” (δι᾽ αἰσθήσεως). This kind is called ‘phantasia,’ perhaps best rendered as “appearing.”1 The purpose of this paper is to uncover the distinction between these two different kinds (...) of belief.2 What distinguishes these two kinds of belief is the believer’s understanding of the thing the belief is about, as a result of the way in which each kind of belief is .. (shrink)

Section 1 contrasts the approaches to Plato of F.M.Cornford and Gilbert Ryle, two of the early twentieth century’s leading Plato interpreters. Then I trace and evaluate attempts to discern in Plato’s Theaetetus a recognition of the role of the proposition. Section 2 focuses on the hunting of the proposition in Socrates’ Dream in the Theaetetus. Ryle, inspired by Logical Atomism, argued that Plato there anticipated an insight about the difference between names and propositions that Russell credited to Wittgenstein. I rehearse (...) difficulties for understanding the logos of the Dream as a proposition, preferring a reading of logos there as something like definition: a reading Wittgenstein also adumbrated. Section 3 examines attempts by writers such as Burnyeat and Kahn to find Plato allocating a starring role to the proposition in the argument at Theaetetus 185–6: perception, since it cannot grasp being, cannot grasp truth and hence cannot be knowledge. On their reading a grasp of being is understood as a grasp of something propositional. Problems for the propositional reading include Socrates’ talk of grasping ‘the truth of something’ (alētheia tinos), and the way the dialogue develops after 186. (shrink)

The goal of this paper is to examine the cognitive limits of aisthêsis in 184-6 of Plato’s Theaetetus. The options are: aisthêsis as ‘bare sensation’ and aisthêsis as ‘perceptual judgment’. I argue that Plato ignores the tension between these two alternatives because he is describing the whole process of perception as containing both. My focus is the text at 184-5, but first I make some preliminary comments, from a synoptic perspective, about what Plato is doing in the context of the (...) argument. After that, I move on the text, offering translations and interpretations of the relevant parts. I also discuss some of Cornford and Cooper’s ideas about Theaetetus 184-6. (shrink)

Selon Platon, la sensation n’est assurément pas en elle-même et par ellemême épistémique, car la science ne comporte rien de sensible, puisqu’elle advient sans l’intervention du corps, tandis que la sensation est précisément une affection qui unit âme et corps dans un même mouvementCe point fait l’objet d’un long passage du Théétète, au cours duquel la thèse de Protagoras selon laquelle science et sensation sont identiques est réfutée. Ceci est bien connu, mais il importe néanmoins de clarifier la raison pour (...) laquelle Platon invalide cette identité, ce qui rend impossible l’assimilation de la sensation à la science, que celle-ci soit, du reste, intuitive ou judicative. (shrink)

In the passage 179c-183b, Plato rejects the extreme Heraclitean explanation of perception by showing that it cannot comply with condition (I): if while perceiving x, x moves, but does not change, it will be possible to describe x as something qualified. This paper intends to show that, for Plato, in order to comply with (I), there must be an explanation of perception in which the perception process is performed by an agent who undertakes other cognitive processes different from perception, such (...) as judging. This is a process through which, for every sensible object x, it is possible to have knowledge of x. (shrink)