In modern times the belief that the ultimate explanation of all things was to be found in Newtonian mechanics was an adumbration of the truth that all science, as it grows towards perfection, becomes mathematical in its ideas.

There are no whole truths: all truths are half-truths. It is trying to treat them as whole truths that plays to the devil.

In a living civilization there is always an element of unrest, for sensitiveness to ideas means curiosity, adventure, change. Civilized order survives on its merits and is transformed by its power of recognizing its imperfections.

We must produce a great age, or see the collapse of the upward striving of our race.

It is the business of the future to be dangerous.

Vigorous societies harbour a certain extravagance of objectives.

Seek simplicity but distrust it.