The ideas of Freud were popularized by people who only imperfectly understood them, who were incapable of the great effort required to grasp them in their relationship to larger truths, and who therefore assigned to them a prominence out of all proportion to their true importance.

The science of pure mathematics, in its modern developments, may claim to be the most original creation of the human spirit.

The greatest invention of the nineteenth century was the invention of the method of invention.

To come very near to a true theory, and to grasp its precise application, are two very differentthings, as the history of a science teaches us. Everything of importance has been said before by somebody who did not discover it.

It is a profoundly erroneous truism, repeated by all copy-books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them. Operations of thought are like cavalry charges in a battle—they are strictly limited in number, they require fresh horses, and must only be made at decisivemoments.

The worship of God is not a rule of safety—it is an adventure of the spirit, a flight after the unattainable.

Heaven knows what seeming nonsense may not tomorrow be demonstrated truth.

The essence of dramatic tragedy is not unhappiness. It resides in the solemnity of the remorseless working of things.

It belongs to the self-respect ot intellect to pursue every tangle of thought to its final unravel- ment.

The importance of an individual thinker owes something to chance. For it depends upon the fate of his ideas in the minds of his successors.