Psycho-analysis has taught us that a boy's earliest choice of objects for his love is incestuous and that those objects are forbidden ones - his mother and his sister. We have learnt, too, the manner in which, as he grows up, he liberates himself from this incestuous attraction. A neurotic, on the other hand, invariably exhibits some degree of psychical infantilism. He has either failed to get free from the psychosexual conditions that prevailed in his childhood or he has returned to them - two possibilities which may be summed up as developmental inhibition and regression.

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

In every age immorality has found no less support in religion than morality has. If the achievements of religion in respect to man's happiness, susceptibility to culture and moral control are no better than this, the question cannot but arise whether we are not overrating its necessity for mankind, and whether we do wisely in basing our cultural demands upon it.

Neurosis is the inability to tolerate ambiguity.

Plaque was placed on 6 May 1977 at Bellevue (a house on the slopes of the Wienerwald) where the Freud family spent their summers.

No one who, like me, conjures up the most evil of those half-tamed demons that inhabit the human breast, and seeks to wrestle with them, can expect to come through the struggle unscathed.

In human beings pure masculinity or femininity is not to be found either in a psychological or biological sense.