Personally, people know themselves very poorly.

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.

Science always has its origin in the adaptation of thought to some definite field of experience.

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.

Ordinarily pleasure and pain are regarded as different from sensations.

The plain man is familiar with blindness and deafness, and knows from his everyday experience that the look of things is influenced by his senses; but it never occurs to him to regard the whole world as the creation of his senses.