We have in fact, two kinds of morality, side by side: one which we preach, but do not practice, and another which we practice, but seldom preach.

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

Religion is based, I think, primarily and mainly upon fear.

Man is the product of causes which had no prevision of the end they were achieving; his origin, his growth, his hopes and fears, his loves and beliefs, are but the outcome of accidental collocations of atoms; no fire, no heroism, no intensity of though and feeling, can preserve an individual life beyond the grave.

... mathematical knowledge ... is, in fact, merely verbal knowledge. "3" means "2+1", and "4" means "3+1". Hence it follows (though the proof is long) that "4" means the same as "2+2". Thus mathematical knowledge ceases to be mysterious.

The method of "postulating" what we want has many advantages; they are the same as the advantages of theft over honest toil.

At the age of eleven, I began Euclid, with my brother as my tutor. This was one of the great events of my life, as dazzling as first love. I had not imagined there was anything so delicious in the world. From that moment until I was thirty-eight, mathematics was my chief interest and my chief source of happiness.