Pathology has made us acquainted with a great number of states in which the boundary lines between the ego and the external world become uncertain or in which they are actually drawn incorrectly. There are cases in which parts of a person's own body, even portions of his own mental life - his perceptions, thoughts and feelings -, appear alien to him and as not belonging to his ego; there are other cases in which he ascribes to the external world things that clearly originate in his own ego and that ought to be acknowledged by it.

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.

The only unnatural sexual behavior is none at all.

Life as we find it is too hard for us; it entails too much pain, too many disappointments, impossible tasks. We cannot do without palliative remedies.

There is a powerful force within us, an un-illuminated part of the mind - separate from the conscious mind that is constantly at work molding our thought, feelings, and actions.

Instinct of love toward an object demands a mastery to obtain it, and if a person feels they can't control the object or feel threatened by it, they act negatively toward it.

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