In the first place a philosophical proposition must be general. It must not deal specially with things on the surface of the earth, or within the solar system, or with any other portion of space and time. . . . This brings us to a second characteristic of philosophical propositions, namely that they must be a priori. A philosophical proposition must be such as can neither be proved nor disproved by empirical evidence. . . . Philosophy, if what has been said is correct, becomes indistinguishable from logic as that word has now come to be used.

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. If you take your children for a picnic on a doubtful day, they will demand a dogmatic answer as to whether it will be fine or wet, and be disappointed in you when you cannot be sure.

The skill of the politician consists in guessing what people can be brought to think advantageous to themselves; the skill of the expert consists in calculating what really is advantageous, provided people can be brought to think so.

Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or ignorance.

Mysticism is, in essence, little more than a certain intensity and depth of feeling in regard to what is believed about the universe.

Ignore fact and reason, live entirely in the world of your own fantastic and myth-producing passions; do this whole-heartedly and with conviction, and you will become one of the prophets of your age.

Cruelty is, in theory, a perfectly adequate ground for divorce, but it may be interpreted so as to become absurd.