Speech is human, silence is divine, yet also brutish and dead: therefore we must learn both arts.
Doubt, of whatever kind, can be ended by action alone.
Time has only a relative existence.
Man is a tool-using animal. Without tools he is nothing, with tools he is all.
The world is a thing that a man must learn to despise, and even to neglect, before he can learn to reverence it, and work in it and for it.
Skepticism . . . is not intellectual only it is moral also, a chronic atrophy and disease of the whole soul.