Democritus — Greek Philosopher

Democritus was an influential Ancient Greek pre-Socratic philosopher primarily remembered today for his formulation of an atomic theory of the universe... (wikipedia)

Nothing exists except atoms and empty space; everything else is opinion.
Happiness resides not in possessions, and not in gold, happiness dwells in the soul.
Raising children is an uncertain thing; success is reached only after a life of battle and worry.
Men should strive to think much and know little.
It is greed to do all the talking but not to want to listen at all.