Science itself, therefore, may be regarded as a minimal problem, consisting of the completest possible presentment of facts with the least possible expenditure of thought.

Mathematics may be defined as the economy of counting. There is no problem in the whole of mathematics which cannot be solved by direct counting.

Many an article that I myself penned twenty years ago impresses me now as something quite foreign to myself.

If our dreams were more regular, more connected, more stable, they would also have more practical importance for us.

Similarly, many a young man, hearing for the first time of the refraction of stellar light, has thought that doubt was cast on the whole of astronomy, whereas nothing is required but an easily effected and unimportant correction to put everything right again.

Man is pre-eminently endowed with the power of voluntarily and consciously determining his own point of view.

Physics is experience, arranged in economical order.