If we knew that god exists, such knowledge would make morality impossible. For, if we acted morally from fear or fright, or confident of a reward, then this would not be moral. It would be enlightened selfishness.

The bad thing of war is, that it makes more evil people than it can take away.

Animals... are there merely as a means to an end. That end is man.

Art is purposiveness without purpose.

The busier we are, the more acutely we feel that we live, the more conscious we are of life.

Upon the solution of this problem, or upon sufficient proof of the impossibility of synthetical knowledge a priori, depends the existence or downfall of metaphysics.

Two things strike me dumb: the infinite starry heavens, and the sense of right and wrong in man.