My pessimism (which, by the way, is far from absolute) originated with my despair in the lack of perfection to be found in human nature. I was attempting in my successive books to show the inevitable handicap of the human condition.

Psychoanalysis provides truth in an infantile, that is, a schoolboy fashion: we learn from it, roughly and hurriedly, things that scandalize us and thereby command our attention. It sometimes happens, and such is the case here, that a simplification touching upon the truth, but cheaply, is of no more value than a lie. Once again we are shown the demon and the angel, the beast and the god locked in Manichean embrace, and once again man has been pronounced, by himself, not culpable.

If a man who can’t count finds a four leaf clover, is he lucky?

Really, one of us ought to have the courage to call the experiment off and shoulder the responsibility for the decision, but the majority reckons that that kind of courage would be a sign of cowardice, and the first step in a retreat. They think it would mean an undignified surrender for mankind as if there was any dignity in floundering and drowning in what we don't understand and never will.

Man has gone out to explore other worlds and other civilizations without having explored his own labyrinth of dark passages and secret chambers, and without finding what lies behind doorways that he himself has sealed.

The first 90% of the job takes 90% of the time. The remaining 10% of the job requires another 90% of the time. The first condition of immortality is death.

A smart machine will first consider which is more worth its while: to perform the given task or, instead, to figure some way out of it.