A man like me cannot live without a hobby-horse, a consuming passion - in Schiller's words a tyrant. I have found my tyrant, and in his service I know no limits. My tyrant is psychology. It has always been my distant, beckoning goal and now since I have hit upon the neuroses, it has come so much the nearer.

We believe that civilization has been created under the pressure of the exigencies of life at the cost of satisfaction of the instincts.

From error to error one discovers the entire truth.

Words have a magical power. They can either bring the greatest happiness or the deepest despair.

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.

Demons do not exist any more than gods do, being only the products of the psychic activity of man.

Religious illusion must bow to scientific truth. It is in total error about the nature of the true world. Only science is not an illusion.