The time comes when each one of us has to give up as illusions the expectations which, in his youth, he pinned upon his fellow-men, and when he may learn how much difficulty and pain has been added to his life by their ill-will.
Sigmund Freud (1856 - 1939)
Source: Civilization and Its Discontents, chapter 5 (1930)
The very emphasis of the commandment: Thou shalt not kill, makes it certain that we are descended from an endlessly long chain of generations of murderers, whose love of murder was in their blood as it is perhaps also in ours.
I have found little that is "good" about human beings on the whole. In my experience most of them are trash, no matter whether they publicly subscribe to this or that ethical doctrine or to none at all. That is something that you cannot say aloud, or perhaps even think. Letter (9 October 1918)
The expectation that every neurotic phenomenon can be cured may, I suspect, be derived from the layman's belief that the neuroses are something quite unnecessary which have no right whatever to exist. Whereas in fact they are severe, constitutionally fixed illnesses, which rarely restrict themselves to only a few attacks but persist as a rule over long periods throughout life.