All failures are so because they lack social interest.

To all those who walk the path of human cooperation war must appear loathsome and inhuman.

Mathematics is pure language - the language of science. It is unique among languages in its ability to provide precise expression for every thought or concept that can be formulated in its terms.

Every therapeutic cure, and still more, any awkward attempt to show the patient the truth, tears him from the cradle of his freedom from responsibility and must therefore reckon with the most vehement resistance.

Play is a child's work and this is not a trivial pursuit.

It is from among such individuals that all human failures spring.

Each generation has its few great mathematicians, and mathematics would not even notice the absence of the others. They are useful as teachers, and their research harms no one, but it is of no importance at all. A mathematician is great or he is nothing.