The purpose of this article is to offer analysis of the passage on evil in the Theaetetus 176a4-8. I submit that it stands in anticipatory relation to Plato’s mature theory of evil, as it can be deduced from the Timaeus. My assumption is that in the Theaetetus passage two contrary principles are postulated, one of which is the cause of good, while the other is the cause of evil. In order to support that assumption, I shall argue that a) Plato’s (...) doctrine of the Forms is present in the Theaetetus Digression; b) the word ‘good’ at 176a6 refers to Plato’s highest entity – αὐτὸ ἀγαθόν; c) τὰ κακά of 176a5 are not to be identified with the opposite of τὸ ἀγαθόν mentioned in the same line; d) the ὑπεναντίον of 176a6, the subordinated opposite of τὸ ἀγαθόν, and the second ἀνάγκη in the passage could denote the same entity, i.e. the Timaean Necessity. (shrink)

With the use of a particular metaphor, which appears at the end of the Cratylus and is taken up with perfect symmetry at the beginning of the Theaetetus, Plato certainly wanted to indicate the succession of Cratylus–Theaetetus as an order for reading the two dialogues, which Trasillus faithfully reproduced in structuring the second tetralogy of Platonic dialogues. The claim of the theory of ideas, with which the Cratylus ends, must therefore be considered the background in which to place not only (...) the analysis of the name carried out in the Cratylus, but also the discussion and criticism of the epistemological theories examined and refuted in the Theaetetus. The transition from the discussion of the name to that of the logos is another important theoretical element that connects the two dialogues. Another one is the theory of knowledge, already precisely elaborated in the Cratylus, and taken up and deepened in the Theaetetus. Finally, the theme of false and error is a third theoretical element common to the two dialogues, which, starting from Euthydemus, finds its solution in the Sophist. (shrink)