There is scarcely room for doubt that something in the psychological relation of a mother-in-law to a son-in-law breeds hostility between them and makes it hard for them to live together. But the fact that in civilized societies mothers-in-law are such a favourite subject for jokes seems to me to suggest that the emotional relation involved includes sharply contrasted components. I believe, that is, that this relation is in fact an 'ambivalent' one, composed of conflicting affectionate and hostile impulses.

It is impossible to overlook the extent to which civilization is built upon a renunciation of instinct.

I have an infamously low capacity for visualizing relationships, which made the study of geometry and all subjects derived from it impossible for me.

When it happens that a person has to give up a sexual object, there quite often ensues an alteration of his ego which can only be described as a setting up of the object inside the ego, as it occurs in melancholia; the exact nature of this substitution is as yet unknown to us.

In the last analysis the entire field of psychology may reduce to biological electrochemistry.

Civilization has little to fear from educated people and brain-workers. In them the replacement of religious motives for civilized behaviors by other, secular motives, would proceed unobtrusively. . . .

Men have gained control over the forces of nature to such an extent that with their help they would have no difficulty exterminating one another to the last man. They know this, and hence comes a large part of their current unrest, their unhappiness and their mood of anxiety.