Our struggle in life requires two virtues, bravery and wisdom -- readiness to endure a danger and skillful knowledge of how to manage it.

Gorgias (the Sophist)

There are intelligible principles inherent in the matter of every phenomenon; because matter is essentially the sum of all the seemings that it has for any and all persons. 

Protagoras (the Sophist)

All things must be either limiting, or unlimited, or both limiting and unlimited.  Since things cannot consist either of the limiting alone or of the unlimited alone ... we must obviously conclude that the universe and its contents are fitted together and harmonized by a combination of the limiting and the unlimited.

For if everything that is were unlimited, there would not be anything of such a character that it could be recognized.

Philolaus  (a Pythagorean)

The wind is blowing; adore the wind.

From the Pythagorean symbola

In everything there is a portion of everything else.

Anaxagoras, (per Philip Wheelwright, The PreSocratics)

To be is possible and not-to-be is impossible.... Thought and being are the same.

Parmenides, (per Philip Wheelwright, The PreSocratics)

Everything flows and nothing abides; everything gives way and nothing stays fixed.... It is in changing that things find repose.

Men who love wisdom should acquaint themselves with a great many particulars.

Heraclitus (per Philip Wheelwright, The PreSocratics)