It is intelligent to have a plan, but neurotic to fall in love with it.

I now see the necessity of a beginning.

[Freud's] sense of reality is less clouded by wishful thinking than is the case with other people and [he combines] the qualities of critical judgment, earnestness and responsibility.

Put your hand on a hot stove for a minute and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute.

There are moments when one feels free from one's own identification with human limitations and inadequacies. At such moments one imagines that one stands on some spot of a small planet, gazing in amazement at the cold yet profoundly moving beauty of the eternal, the unfathomable; life and death flow into one, and there is neither evolution nor destiny; only Being.

You believe in the God who plays dice, and I in complete law and order in a world that objectively exists, and which I, in a wildly speculative way, am trying to capture. ... Even the great initial success of the quantum theory does not make me believe in the fundamental dice-game, although I am well aware that our younger colleagues interpret this as a consequence of senility. No doubt the day will come when we will see whose instinctive attitude was the correct one.

Everything has changed except the way man thinks (when the hydrogen bomb was exploded)