It seems to be the fate of idealists to obtain what they have struggled for in a form which destroys their ideals.

Those whose lives are fruitful to themselves, to their friends, or to the world are inspired by hope and sustained by joy: they see in imagination the things that might be and the way in which they are to be brought into existence.

Man can be stimulated by hope or driven by fear, but the hope and the fear must be vivid and immediate if they are to be effective without producing weariness.

Abstract work, if one wishes to do it well, must be allowed to destroy one's humanity; one raises a monument which is at the same time a tomb, in which, voluntarily, one slowly inters oneself.

Arithmetic must be discovered in just the same sense in which Columbus discovered the West Indies, and we no more create numbers than he created the Indians.

But courage in fighting is by no means the only form, nor perhaps even the most important. There is courage in facing poverty, courage in facing derision, courage in facing the hostility of one's own herd. In these, the bravest soldiers are often lamentably deficient. And above all there is the courage to think calmly and rationally in the face of danger, and to control the impulse of panic fear or panic rage.

I am delighted to know that Principia Mathematica can now be done by machinery. . . I am quite willing to believe that anything in deductive logic can be done by machinery.