While the dogmatist is harmful, the sceptic is useless ...; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or of ignorance. Knowledge is not so precise a concept as is commonly thought. Instead of saying 'I know this', we ought to say 'I more or less know something more or less like this'. ... Knowledge in practical affairs has not the certainty or the precision of arithmetic.

[There are m]oral precepts that we consider really important, such as 'don't pick your nose' or 'don't eat peas with a knife'. There may, for ought I know, be admirable reasons for eating peas with a knife, but . . . early persuasion has made me completely incapable of appreciating them.

Of these austerer virtues the love of truth is the chief, and in mathematics, more than elsewhere, the love of truth may find encouragement for waning faith. Every great study is not only an end in itself, but also a means of creating and sustaining a lofty habit of mind; and this purpose should be kept always in view throughout the teaching and learning of mathematics.

Laughter is the most inexpensive and most effective wonder drug. Laughter is a universal medicine.

The taboo against nakedness is an obstacle to a decent attitude on the subject of sex.

Boys and girls should be taught respect for each other's liberty... and that jealousy and possessiveness kill love.

I read Zuleika Dobson with pleasure. It represents the Oxford that the two World Wars have destroyed with a charm that is not likely to be reproduced anywhere in the world for the next thousand years.