Bring forward what is true, Write it so that it is clear, Defend it to your last breath!

Which is more remarkable fact about America: that millionaires are idealists or idealists become millionaires.

Nothing is more practical than a good theory.

The most ordinary things are to philosophy a source of insoluble puzzles. With infinite ingenuity it constructs a concept of space or time and then finds it absolutely impossible that there be objects in this space or that processes occur during this time . . . the source of this kind of logic lies in excessive confidence in the so-called laws of thought.

Available energy is the main object at stake in the struggle for existence and the evolution of the world.

In my view all salvation for philosophy may be expected to come from Darwin's theory

A mathematician will recognise Cauchy, Gauss, Jacobi or Helmholtz after reading a few pages, just as musicians recognise, from the first few bars, Mozart, Beethoven or Schubert.