You can never be overdressed or overeducated.
Education consists mainly of what we have unlearned.
What could an entirely rational being speak of with another entirely rational being?
Worse than any severe mental illness, is the illness of bigotry.
It is no small art to sleep: for that purpose you must keep awake all day.
Man once surrendering his reason, has no remaining guard against absurdities the most monstrous, and like a ship without rudder, is the sport of every wind.
A man who dares to waste one hour of time has not discovered the value of life.
Natural science does not simply describe and explain nature: it is part of the interplay between us and nature.
The hour of departure has arrived, and we go our ways. I to die, and you to live. Which is better God only knows.