Cratylus (412)

Socrates.Σωφροσύνη (self-restraint) is σωτηρία (salvation) of φρόνησις (wisdom), which we have just been discussing. And ἐπιστήμη (knowledge) indicates that the soul which is of any account accompanies (ἕπεται) things in their motion, neither falling behind them nor running in front of them; therefore we ought to insert an epsilon and call it ἐπεϊστήμη. Σύνεσις (intelligence) in its turn is a kind of reckoning together; when one says συνιέναι (understand), the same thing as ἐπίστασθαι is said; for συνιέναι means that the soul goes with things. Certainly σοφία (wisdom) denotes the touching of motion. This word is very obscure and of foreign origin; but we must remember that the poets often say of something which begins to advance ἐσύθη (it rushed). There was a famous Laconian whose name was Σοῦς (Rush), for this is the Laconian word for rapid motion. Now σοφία signifies the touching (ἐπαφή) of this rapid motion, the assumption being that things are in motion. And the word ἀγαθόν (good) is intended to denote the admirable (ἀγαστόν) in all nature. For since all things are in motion, they possess quickness and slowness; now not all that is swift, but only part of it, is admirable; this name ἀγαθόν is therefore given to the admirable (ἀγαστόν) part of the swift (θοοῦ). It is easy to conjecture that the word δικαιασύνη applies to the understanding (σύνεσις) of the just (τοῦ διαίον) but the word δίκαιον (just) is itself difficult. Up to a certain point, you see, many men seem to agree about it, but beyond that they differ. For those who think the universe is in motion believe that the greater part of it is of such a nature as to be a mere receptacle, and that there is some element which passes through all this, by means of which all created things are generated. And this element must be very rapid and very subtle; for it could not pass through all the universe unless it were very subtle, so that nothing could keep it out, and it must be very swift, so that all other things are relatively at rest. Since, then, it superintends and passes through (διαϊόν) all other things, this is rightly called by the name δίκαιον, the sound of the kappa being added merely for the sake of euphony.