Sigmund Freud

The great question that has never been answered and which I have not yet been able to answer, despite my thirty years of research into the feminine soul, is 'What does a woman want?'

The tendency of aggression is an innate, independent, instinctual disposition in man . . . it constitutes the most powerful obstacle to culture.

The time comes when each one of us has to give up as illusions the expectations which, in his youth, he pinned upon his fellow-men, and when he may learn how much difficulty and pain has been added to his life by their ill-will.

The very emphasis of the commandment: Thou shalt not kill, makes it certain that we are descended from an endlessly long chain of generations of murderers, whose love of murder was in their blood as it is perhaps also in ours.

When a man has once brought himself to accept uncritically all the absurdities that religious doctrines put before him and even to overlook the contradictions between them, we need not be greatly suprised at the weakness of his intellect.

Religious ideas have sprung from the same need as all the other achievements of culture: from the necessity for defending itself against the crushing supremacy of nature.

Obviously one must hold oneself responsible for the evil impulses of one's dreams. In what other way can one deal with them? Unless the content of the dream rightly understood is inspired by alien spirits, it is part of my own being.

No, our science is no illusion. But an illusion it would be to suppose that what science cannot give us we can get elsewhere.

We are never so defenseless against suffering as when we love, never so forlornly unhappy as when we have lost our love object or its love.

I have found little that is "good" about human beings on the whole. In my experience most of them are trash, no matter whether they publicly subscribe to this or that ethical doctrine or to none at all. That is something that you cannot say aloud, or perhaps even think. Letter (9 October 1918)