Heraclitus (Stanford Encyclopedia of Philosophy)

Learning many things does not teach understanding. Else it would have taught Hesiod and Pythagoras, as well as Xenophanes and Hecataeus.

As the same thing in us are living and dead, waking and sleeping, young and old. For these things having changed around are those, and those in turn having changed around are these.

Collections: wholes and not wholes; brought together, pulled apart; sung in unison, sung in conflict; from all things one and from one all things

Sea is the purest and most polluted water: for fish drinkable and healthy, for men undrinkable and harmful.