did not in fact separate universals from their instances cannot have been derived from Aristotle’s reading of Plato, and the inference is irresistible that its source was oral tradition in the Academy stemming ultimately from Plato himself. We do not have to suppose either that Aristotle was personally intimate with Plato, his senior by over forty years (though he is said to have been a favourite pupil, and he wrote a poem in praise of Plato), or that personal reminiscences of Socrates were a staple topic of discussion in the Academy. All that we need suppose is that some basic facts about the role of Socrates vis-à-vis Plato were common knowledge in the school. It would have been astonishing had that not been so, and the scepticism of some modern scholars on this point is altogether unreasonable. How much this tradition included, beyond the fact that Socrates did not separate the Forms, it is impossible to say. I find it plausible that it included the two positive assertions which Aristotle associates with that negative one,namely, that Socrates looked for universal definitions and that he used inductive arguments.
Plato
Socrates appears in every Platonic dialogue except the Laws , universally agreed to be Plato’s last work. So, strictly speaking, all of Plato’s writings, with the exception of the Laws , the Apology (which is not a dialogue), and the Letters (whose authenticity is disputed) are Socratic dialogues. There are, however, considerable variations in the presentation of the figure of Socrates over the corpus as a whole. In two dialogues acknowledged on stylistic grounds to be late works, the Sophist and the Statesman , Socrates appears only in the introductory conversation which serves to link those two dialogues to one another and to Theaetetus , while the role of the principal participant in the main conversation, normally assigned to Socrates, is assigned to a stranger from Elea (i.e. to a representative of the philosophy of Parmenides). The same situation occurs in two other late dialogues, Timaeus and its unfinished sequel Critias ; in each case Socrates figures briefly in the introductory conversation and the main speaker is the person who gives his name to the dialogue. In Parmenides Socrates appears, uniquely, as a very young man, whose main role is to be given instruction in philosophical method by the elderly Parmenides. Even the dialogues where Socrates is the main speaker exhibit considerable variation in portrayal. Some give prominence to events in Socrates’ life, notably Symposium and those works centred on his trial and death ( Euthyphro, Apology , Crito , and Phaedo ), but also (to a lesser extent) Charmides . Some, including those just mentioned, contain lively depictions of the personality of Socrates and of argumentative interchanges between him and others, with particular prominence given to sophists and their associates. In this group, besides those just mentioned, fall Protagoras , Gorgias , Euthydemus , Meno , Republic 1, Hippias Major , Hippias Minor , Ion , Laches , and Lysis . In others again, though Socrates is the principal figure in the sense of directing thecourse of the discussion, he is much less of an individual personality, and more of a representative figure of philosophical authority, replacable, for all the difference it would make to the course of the discussion, by another; for example, the Eleatic Stranger (or, perhaps, Plato). Such seems to me (though this is a matter for individual judgement) the role of Socrates in Republic (except book 1), Phaedrus , Cratylus , Theaetetus , and Philebus . How is this plasticity in Plato’s portrayal of Socrates to be accounted for, and what are its implications for the relation between that portrayal and the historical Socrates?
In the nineteenth century investigations of stylistic features of the dialogues by various scholars converged independently on the identification of six dialogues: Sophist , Statesman , Philebus ,