This paper is a test case for the claim, made famous by Myles Burnyeat, that the ancient Greeks did not recognize subjective truth or knowledge. After a brief discussion of the issue in Sextus Empiricus, I then turn to Plato's discussion of Protagorean views in the Theaetetus. In at least two passages, it seems that Plato attributes to Protagoras the view that our subjective experiences constitute truth and knowledge, without reference to any outside world of objects. I argue that these (...) passages have been misunderstood and that on the correct reading, they do not say anything about subjective knowledge. I then try out what I take to be the correct reading of the passages. The paper concludes with a brief discussion of the importance of causes in Greek epistemology. (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)

Two readings of the much-discussed περιτροπή argument of "Theaetetus" 170c-171c have dominated the literature. One I call "the relativity reading". On this reading, the argument fails by ignoratio elenchi because it "carelessly" omits "the qualifications 'true for so-and-so' which [Protagoras'] theory insists on" (Bostock 1988: 90). The other reading I call "the many-worlds interpretation". On this view, Plato's argument succeeds in showing that "Protagoras' position becomes utterly self-contradictory" because "he claims that everyone lives in his own relativistic world, yet at (...) the same time he is forced by that very claim to admit that no one does" (Burnyeat 1976b: 48). I discuss and criticise both readings, and present a third, according to which the point of the argument is, very roughly, that Protagoras is committed to equating truth and truth-for, and so, further, to their intersubstitutability. This further commitment proves fatal to his argument. (shrink)

Two readings of the much-discussed περιτροπή argument of "Theaetetus" 170c-171c have dominated the literature. One I call "the relativity reading". On this reading, the argument fails by ignoratio elenchi because it "carelessly" omits "the qualifications 'true for so-and-so' which [Protagoras'] theory insists on" (Bostock 1988: 90). The other reading I call "the many-worlds interpretation". On this view, Plato's argument succeeds in showing that "Protagoras' position becomes utterly self-contradictory" because "he claims that everyone lives in his own relativistic world, yet at (...) the same time he is forced by that very claim to admit that no one does" (Burnyeat 1976b: 48). I discuss and criticise both readings, and present a third, according to which the point of the argument is, very roughly, that Protagoras is committed to equating truth and truth-for, and so, further, to their intersubstitutability. This further commitment proves fatal to his argument. (shrink)

The paper offers an interpretation of a disputed portion of Plato’s Theaetetus that is often called the Secret Doctrine. It is presented as a process ontology that takes two types of processes, swift and slow motions, as fundamental building blocks for ordinary material objects. Slow motions are powers which, when realized, generate swift motions, which, in turn, are subjectively bundled to compose sensible objects and perceivers. Although the reading of the Secret Doctrine offered here—a new version of the “Causal Theory (...) interpretation”—is not without problems, these problems are acknowledged in Plato’s text, confirming that this interpretation is correct. (shrink)