No one who achieves success does so without acknowledging the help of others. The wise and confident acknowledge this help with gratitude.

No Roman ever died in contemplation over a geometrical diagram.

By relieving the brain of all unnecessary work, a good notation sets it free to concentrate on more advanced problems, and in effect increases the mental power of the race.

Not ignorance, but ignorance of ignorance, is the death of knowledge.

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

I am also greatly indebted to Bergson, William James, and John Dewey. One of my preoccupations has been to rescue their type of thought from the charge of anti-intellectualism, which rightly or wrongly has been associated with 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.