Up to now, we have spoken solely of oral dialogue as it must have been practiced within the Academy. We can only imagine what this dialogue must have been like, by means of the examples we find in Plato’s written work; and in order to simplify things, we have often quoted them using the phrase “as Plato says.” Yet this expression is quite inexact, for Plato, in his written works, never says anything in his own voice. Whereas Xenophanes, Parmenides, Empedocles, the Sophists, and Xenophon had not hesitated to write in the first person, Plato makes fictional characters speak within fictional situations. Only in the Seventh Letter does he allude to his philosophy, and when he does he describes it more as a way of life. Above all, he declares that with regard to the object of his concerns, he has not published any written work, nor will he ever do so, for the knowledge in question cannot under any circumstances be formulated like other bodies of knowledge. Instead, it springs forth within the soul, when one has long been familiar with the activity in which it consists and has devoted one’s life to it.
Pierre Hadot, “What is Ancient Philosophy?”