Obviousness is always the enemy of correctness.

Frege has the merit of ... finding a third assertion by recognising the world of logic which is neither mental nor physical.

There are infinite possibilities of error, and more cranks take up fashionable untruths than unfashionable truths.

When conscious activity is wholly concentrated on some one definite purpose, the ultimate result, for most people, is lack of balance accompanied by some form of nervous disorder.

Philosophy, for Plato, is a kind of vision, the 'vision of truth'...Everyone who has done any kind of creative work has experienced, in a greater or less degree, the state of mind in which, after long labour, truth or beauty appears, or seems to appear, in a sudden glory - it may only be about some small matter, or it may be about the universe. I think that most of the best creative work, in art, in science, in literature, and in philosophy, has been a result of just such a moment.

Ignore fact and reason, live entirely in the world of your own fantastic and myth-producing passions; do this whole-heartedly and with conviction, and you will become one of the prophets of your age.

Science tells us what we can know, but what we can know is little, and if we forget how much we cannot know we become insensitive to many things of great importance.