Against my will, in the course of my travels, the belief that everything worth knowing was known at Cambridge gradually wore off. In this respect my travels were very useful to me.

Even in civilized mankind faint traces of monogamous instinct can be perceived.

Envy is the basis of democracy.

None of our beliefs are quite true; all have at least a penumbra of vagueness and error.

Freedom comes only to those who no longer ask of life that it shall yield them any of those personal goods that are subject to the mutations of time.

I think periods of browsing during which no occupation is imposed from without are important in youth because they give time for the formation of these apparently fugitive but really vital impressions.

Humanistic ethics is based on the principle that only humans themselves can determine the criterion for virtue and not an authority transcending us.