But perhaps you will say that though reason asserts that the Cynic, who alone of men can claim to be free, ought not to invent and compose lying fictions instead of the unvarnished truth and then recite these in public assemblies, nevertheless the custom began with Diogenes and Crates, and has been maintained from that time by all Cynics. My answer is that nowhere will you find a single example of such a custom. For the moment I do not insist on the fact that it in no wise becomes a Cynic who must “give a new stamp to the common currency” to pay any attention to custom, but only to pure reason, and he ought to discover within himself what is right for him to do and not learn it from without. And do not be misled by the fact that Antisthenes the disciple of Socrates, and Xenophon too, sometimes expressed themselves by means of myths; for I shall have something to say to you on this point in a moment.
Source: The Works of the Emperor Julian, volume II (1913) Loeb Classical Library. Translated by Emily Wilmer Cave Wright.