The view is often defended that sciences should be built up on clear and sharply defined basal concepts. In actual fact no science, not even the most exact, begins with such definitions. The true beginning of scientific activity consists rather in describing phenomena and then in proceeding to group, classify and correlate them.

There is an intellectual function in us which demands unity, connection and intelligibility from any material, whether of perception or thought, that comes within its grasp; and if, as a result of special circumstances, it is unable to establish a true connection, it does not hesitate to fabricate a false one.

I do not in the least underestimate bisexuality... I expect it to provide all further enlightenment.

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

A lady once expressed herself in society - the very words show that they were uttered with fervour and under the pressure of a great many secret emotions: "Yes, a woman must be pretty if she is to please the men. A man is much better off. As long as he has five straight limbs, he needs no more!"

The act of birth is the first experience of anxiety, and thus the source and prototype of the affect of anxiety.

I take up the standpoint that the tendency to aggression is an innate, independent, instinctual disposition in man, and I come back now to the statement that it constitutes the most powerful obstacle to culture.