Science will stagnate if it is made to serve practical goals.

The high destiny of the individual is to serve rather than to rule.

The pioneers of a warless world are the young men (and women) who refuse military service.

It is true that my parents were worried because I began to speak fairly late, so that they even consulted a doctor. I can't say how old I was - but surely not less than three.

Long hair minimizes the need for barbers; socks can be done without; one leather jacket solves the coat problem for many years; suspenders are superfluous.

My interest in science was always essentially limited to the study of principles.... That I have published so little is due to this same circumstance, as the great need to grasp principles has caused me to spend most of my time on fruitless pursuits.

[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.