At bottom God is nothing more than an exalted father.

The more the fruits of knowledge become accessible to men, the more widespread is the decline of religious belief.

Just as a satisfaction of instinct spells happiness for us, so severe suffering is caused us if the external world lets us starve, if it refuses to sate our needs. One may therefore hope to be freed from a part of one's sufferings by influencing the instinctual impulses.

No one who, like me, conjures up the most evil of those half-tamed demons that inhabit the human breast, and seeks to wrestle with them, can expect to come through the struggle unscathed.

Where questions of religion are concerned, people are guilty of every possible sort of dishonesty and intellectual misdemeanor.

What progress we are making. In the Middle Ages they would have burned me. Now they are content with burning my books.

It sounds not only disagreeable but also paradoxical, yet it must nevertheless be said that anyone who is to be really free and happy in love must have surmounted his respect for women and have come to terms with the idea of incest with his mother or sister.