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.

An open mind is all very well in its way, but it ought not to be so open that there is no keeping anything in or out of it.

It is not paradox to say that in our most theoretical moods we may be nearest to our most practical applications.

What the learned world tends to offer is one second-hand scrap of information illustrating ideas derived from another second-hand scrap of information. The second-handedness of the learned world is the secret of its mediocrity.

It is impossible to meditate on time and the mystery of nature without an overwhelming emotion at the limitations of human intelligence.

I have suffered a great deal from writers who have quoted this or that sentence of mine either out of its context or in juxtaposition to some incongruous matter which quite distorted my meaning, or destroyed it altogether.

No reason can be given for the nature of God, because that nature is the ground of rationality.