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.

An intimate friend and a hated enemy have always been indispensable requirements for my emotional life; I have always been able to create them anew, and not infrequently my childish ideal has been so closely approached that friend and enemy coincided in the same person.

The unconscious of one human being can react upon that of another without passing through the conscious.

The facts which have caused us to believe in the dominance of the pleasure principle in mental life also find expression in the hypothesis that the mental apparatus endeavours to keep the quantity of excitation present in it as low as possible or at least to keep it constant.

Intelligence will be used in the service of the neurosis.

There is no doubt that the resistance of the conscious and unconscious ego operates under the sway of the pleasure principle: it seeks to avoid the unpleasure which would be produced by the liberation of the repressed.

Sadism is all right in its place, but it should be directed to proper ends.