Error is the price we pay for progress.

No man of science wants merely to know. He acquires knowledge to appease his passion for discovery. He does not discover in order to know, he knows in order to discover.

How the past perishes is how the future becomes.

I have always noticed that deeply and truly religious persons are fond of a joke, and I am suspicious of those who aren't.

Intelligence is quickness to apprehend as distinct form ability, which is capacity to act wisely on the thing apprehended.

No period of history has ever been great or ever can be that does not act on some sort of high, idealistic motives, and idealism in our time has been shoved aside, and we are paying the penalty for it.

The Universe is vast. Nothing is more curious than the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of existing modes of knowledge. Skeptics and believers are alike. At this moment scientists and skeptics are the leading dogmatists. Advance in detail is admitted; fundamental novelty is barred. This dogmatic common sense is the death of philosophic adventure.