Life is a value to be bought and thinking is the only coin noble enough to buy it.

An animal is equipped for sustaining its life; its senses provide it with an automatic code of action, an automatic knowledge of what is good for it or evil... Man has no automatic code of survival. His particular distinction from all other living species is the necessity to act in the face of alternatives by means of volitional choice.

I want to be prepared to claim the greatest virtue of all - that I was a man who made money

One loses everything when one loses one's sense of humor.

Whether you know the shape of a pebble or the structure of a solar system, the anxioms remain the same: that it exists and that you know it.

Whatever road I take, the guiding star is within me; the guiding star and the loadstone which point the way. They point in but one direction. They point to me.

Andrei, did you like the opera?" "Not particularly." "Andrei, do you see what you're missing?" "I don't think I do, Kira. It's all rather silly. And useless." "Can't you enjoy things that are useless, merely because they are beautiful?" "No. But I enjoyed it." "The music?" "No. The way you listened to it.