The deepest definition of youth is life as yet untouched by tragedy

Civilization advances by extending the number of important operations which we can perform without thinking about them.

It is a safe rule to apply that, when a mathematical or philosophical author writes with a misty profundity, he is talking nonsense.

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.

The study of mathematics is apt to commence in disappointment... We are told that by its aid the stars are weighed and the billions of molecules in a drop of water are counted. Yet, like the ghost of Hamlet's father, this great science …

The aim of science is to seek the simplest explanations of complex facts. We are apt to fall into the error of thinking that the facts are simple because simplicity is the goal of our quest. The guiding motto in the life of every natural …

Life is complex in its expression, involving more than percipience, namely desire, emotion, will, and feeling. ... identification of rhythm as the causal counterpart of life; wherever there is some life, only perceptible to us when the …