It is not good for a man to be too cognizant of his physical and spiritual mechanisms. Complete knowledge reveals limits to human possibilities, and the less a man is by nature limited in his purposes, the less he can tolerate limits.

Really, one of us ought to have the courage to call the experiment off and shoulder the responsibility for the decision, but the majority reckons that that kind of courage would be a sign of cowardice, and the first step in a retreat. They think it would mean an undignified surrender for mankind as if there was any dignity in floundering and drowning in what we don't understand and never will.

Is a mountain only a huge stone? Is a planet an enormous mountain?

Our ability to adapt and therefore to accept everything is one of our greatest dangers. Creatures that are completely flexible, changeable, can have no fixed morality.

Man does not create gods, in spite of appearances. The times, the age, impose them on him.

The night stared me in the face, amorphous, blind, infinite, without frontiers. Not a single start relieved the darkness behind the glass.

Man does not create gods, in spite of appearances. The times, the age, impose them on him. Man can serve his age or rebel against it, but the target of his cooperation or rebellion comes to him from outside.