Prophets, mystics, poets, scientific discoverers are men whose lives are dominated by a vision; they are essentially solitary men . . . whose thoughts and emotions are not subject to the dominion of the herd.

The first man who said "fire burns" was employing scientific method, at any rate if he had allowed himself to be burnt several times. This man had already passed through the two stages of observation and generalization. He had not, however, what scientific technique demands - a careful choice of significant facts on the one hand, and, on the other hand, various means of arriving at laws otherwise than my mere generalization.

The slave is doomed to worship time and fate and death, because they are greater than anything he finds in himself, and because all his thoughts are of things which they devour.

The universe may have a purpose, but nothing we know suggests that, if so, this purpose has any similarity to ours.

If the West can claim superiority in anything, it is . . . in science and scientific technique.

Whatever we know without inference is mental.

It is the things for which there is no evidence that are believed with passion.