That he should do so was only natural, since his position as a teacher of rhetoric was already secure when Protagoras made his first appearance in the character of a sophist; and, as Protagoras, Prodicus and the rest of the sophists of culture offered a comprehensive education, of which oratory formed only a part, whilst Gorgias made no pretence of teaching " civic excellence " (Plato, Meno, 95 C), and found a substitute for philosophy, not in literature generally, but in the professional study of rhetoric alone, it would have been convenient if the distinction between sophistry and rhetoric had been maintained.
Distrusting tradition, he took a few of the finest dialogues as his standard, and from internal evidence denounced as spurious not only those which are generally admitted to be so (Epinomis, Minos, Theages, Arastae, Clitophon, Hipparchus, Eryxias, Letters and Definitions), but also the Meno, Euthydemus, Charmides, Lysis, Laches, First and Second Alcibiades, Hippias Major and Minor, Ion, Euthyphro, Apology, Crito, and even (against Aristotle's explicit assertion) The Laws.
The Timaeus of Plato in the Latin version of Chalcidius was known to him as to his contemporaries and predecessors, and probably he had access to translations of the Phaedo and Meno.
In 1491 he was at Cork as the servant of a Breton silk merchant Pregent (Pierre Jean) Meno.
Thus the Protagoras brings the educational theory of Protagoras and the sophists of culture face to face with the educational theory of Socrates, so as to expose the limitations of both; the Gorgias deals with the moral aspect of the teachings of the forensic rhetorician Gorgias and the political rhetorician Isocrates, and the intellectual aspect of their respective theories of education is handled in the Phaedrus; the Meno on the one hand exhibits the strength and the weakness of the teaching of Socrates, and on the other brings into view the makeshift method of those who, despising systematic teaching, regarded the practical politician as the true educator; the Euthydemus has for its subject the eristical method; finally, having in these dialogues characterized the current theories of education, Plato proceeds in the Republic to develop an original scheme.