We will have to give up taking things for granted, even the apparently simple things.

The psychology of a complex mind must differ almost as much from that of a simple, mechanized mind as its psychology would from ours; because something that must underlie and perhaps be even greater than sex is involved.

The human mind evolved always in the company of the human body, and of the animal body before it was human. The intricate connections of mind and body must exceed our imagination, as from our point of view we are peculiarly prevented from observing them.

The greater the man, the more he is soaked in the atmosphere of his time; only thus can he get a wide enough grasp of it to be able to change substantially the pattern of knowledge and action.

All that glitters may not be gold, but at least it contains free electrons.

Naturalism aimed at giving the primitive wishes full play but failed because these wishes are too primitive, too infantile, too inconsistent with themselves to be satisfied even by the greatest license.

We academic scientists move within a certain sphere, we can go on being useless up to a point, in the confidence that sooner or later some use will be found for our studies. The mathematician, of course, prides himself on being totally useless, but usually turns out to be the most useful of the lot. He finds the solution but he is not interested in what the problem is: sooner or later, someone will find the problem to which his solution is the answer.