Heraclitus (540 BC-480 BC)

Heraclitus was an ancient Greek pre-Socratic philosopher from the city of Ephesus, which was then part of the Persian Empire. He exerts a wide influence on Western philosophy, both ancient and modern, through the works of such authors as Plato, Aristotle, Georg Wilhelm Friedrich Hegel, Friedrich Nietzsche, and Martin Heidegger.

Quotes

Nothing endures but change.

Change
A man's character is his guardian divinity.
All is flux, nothing stays still.
Nature is wont to hide herself.

Nature
Much learning does not teach understanding.

Learning, Understanding
You could not step twice into the same river; for other waters are ever flowing on to you.
The road up and the road down is one and the same.
It is better to hide ignorance, but it is hard to do this when we relax over wine.

Drinking
A man's character is his fate.

Character, Fate
If it were not for injustice, men would not know justice.

Justice
Abundance of knowledge does not teach men to be wise.

Knowledge
You cannot step twice into the same river.
There is nothing permanent except change.