Theaetetus (180)

THEO. Certainly we must. For it is no more possible, Socrates, to discuss these doctrines of Heracleitus (or, as you say, of Homer or even earlier sages) with the Ephesians themselves—those, at least, who profess to be familiar with them—than with madmen. For they are, quite in accordance with their text-books, in perpetual motion; but as for keeping to an argument or a question and quietly answering and asking in turn, their power of doing that is less than nothing; or rather the words nothing at all fail to express the absence from these fellows of even the slightest particle of rest. But if you ask one of them a question, he pulls out puzzling little phrases, like arrows from a quiver, and shoots them off; and if you try to get hold of an explanation of what he has said, you will be struck with another phrase of novel and distorted wording, and you never make any progress whatsoever with any of them, nor do they themselves with one another, for that matter, but they take very good care to allow nothing to be settled either in an argument or in their own minds, thinking, I suppose, that this is being stationary; but they wage bitter war against the stationary, and, so far as they can, they banish it altogether.

SOC. Perhaps, Theodorus, you have seen the men when they are fighting, but have not been with them when they are at peace; for they are no friends of yours; but I fancy they utter such peaceful doctrines at leisure to those pupils whom they wish to make like themselves.

THEO. What pupils, my good man? Such people do not become pupils of one another, but they grow up of themselves, each one getting his inspiration from any chance source, and each thinks the other knows nothing. From these people, then, as I was going to say, you would never get an argument either with their will or against it; but we must ourselves take over the question and investigate it as if it were a problem of mathematics.

SOC. Yes, what you say is reasonable. Now as for the problem, have we not heard from the ancients, who concealed their meaning from the multitude by their poetry, that the origin of all things is Oceanus and Tethys, flowing streams, and that nothing is at rest and likewise from the modern, who, since they are wiser, declare their meaning openly, in order that even cobblers may hear and know their wisdom and may cease from the silly belief that some things are at rest and others in motion, and, after learning that everything is in motion, may honor their teachers? But, Theodorus, I almost forgot that others teach the opposite of this,

So that it is motionless, the name of which is the All,

Parmenides, line 98 (ed. Mullach) [*] and all the other doctrines maintained by Melissus and Parmenides and the rest, in opposition to all these they maintain that everything is one and is stationary within itself, having no place in which to move.