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.
It would be one of the greatest triumphs of humanity, one of the most tangible liberations from the constraints of nature to which mankind is subject, if we could succeed in raising the responsible act of procreating children to the level of a deliberate and intentional activity and in freeing it from its entanglement with the necessary satisfaction of a natural need.
One feels inclined to say that the intention that man should be 'happy' is not included in the plan of Creation.' . . . We are so made that we can derive intense enjoyment only from a contrast and very little from a state of things.