Mathematics is only the art of saying the same thing in different words.

Men fear thought as they fear nothing else on earth - more than ruin, more even than death. Thought is subversive and revolutionary, destructive and terrible, thought is merciless to privilege, established institutions, and comfortable habits; thought is anarchic and lawless, indifferent to authority, careless of the well-tried wisdom of the ages. Thought looks into the pit of hell and is not afraid ... Thought is great and swift and free, the light of the world, and the chief glory of man.

No satisfaction based upon self-deception is solid, and however unpleasant the truth may be, it is better to face it once and for all, to get used to it, and to proceed to build your life in accordance with it.

Even if it is indifferent to human desires, as it seems to be; if human life is a passing episode, hardly noticeable in the vastness of cosmic processes; if there is no superhuman purpose, and no hope of ultimate salvation, it is better to know and acknowledge this truth than to endeavor, in futile self-assertion, to order the universe to be what we find comfortable.

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

Every advance in civilization has been denounced as unnatural while it was recent

Dogmatism is the greatest of mental obstacles to human happiness.