The deepest sin against the human mind is to believe things without evidence.
He who opens a school door, closes a prison.
A concept is a brick. It can be used to build a courthouse of reason. Or it can be thrown through the window.
Spoon feeding in the long run teaches us nothing but the shape of the spoon.
What counts now are the value-less facts, the material and the rational. All else is regarded with condescension as being of only sentimental value.
Kindness is the language which the deaf can hear and the blind can see.
The smallest minority on earth is the individual. Those who deny individual rights cannot claim to be defenders of minorities.
If you’re afraid – don’t do it, – if you’re doing it – don’t be afraid.
Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.
You cannot conquer a free man. The most you can do is kill him.