The world is no nursery.

That which we can't remember, we will repeat.

Neither in my private life nor in my writings, have I ever made a secret of being an out-and-out unbeliever.

The adoption of the required attitude of mind towards ideas that seem to emerge "of their own free will" and the abandonment of the critical function that is normally in operation against them seem to be hard of achievement for some people. The "involuntary thoughts" are liable to release a most violent resistance, which seeks to prevent their emergence. If we may trust that great poet and philosopher Friedrich Schiller, however, poetic creation must demand an exactly similar attitude.

Smoking is indispensable if one has nothing to kiss.

A strong egoism is a protection against disease, but in the last resort we must begin to love in order that we may not fall ill, and must fall ill if, in consequence of frustration, we cannot love.

Our possibilities of happiness are already restricted by our constitution. Unhappiness is much less difficult to experience. We are threatened with suffering from three directions: from our own body, which is doomed to decay and dissolution and which cannot even do without pain and anxiety as warning signals; from the external world, which may rage against us with overwhelming and merciless forces of destruction; and finally from our relations to other men. The suffering which comes from this last source is perhaps more painful to us than any other.