Every really new idea looks crazy at first.

It is the business of the future to be dangerous; and it is among the merits of science that it equips the future for its duties.

The ultimate metaphysical ground is the creative advance into novelty.

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.

Philosophy is the self-correction by consciousness of its own initial excess of subjectivity.

There are no whole truths: All truths are half-truths.

The only use of knowledge of the past is to equip us for the present.