Heraclitus somewhere says that all things are in process and nothing stays still, and likening existing things to the stream of a river he says that you would not step twice into the same river.

The way up and the way down are one and the same.

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

There is nothing permanent except change.

Under the comb, the tangle and the straight path are the same.

There is but one world common for those who are awake, but when men are asleep, each turns away into a world of his own.

Those who are awake all live in the same world. Those who are asleep live in their own worlds.