What is wanted is not the will to believe, but the will to find out, which is the exact opposite.

Morally, a philosopher who uses his professional competence for anything except a disinterested search for truth is guilty of a kind of treachery.

Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true.

Science tells us what we can know but what we can know is little and if we forget how much we cannot know we become insensitive of many things of very great importance. Theology, on the other hand induces a dogmatic belief that we have knowledge where in fact we have ignorance and by doing so generates a kind of impertinent insolence towards the universe. Uncertainty in the presence of vivid hopes and fears is painful, but must be endured if we wish to live without the support of comforting fairy tales.

In the daily lives of most men and women, fear plays a greater part than hope: they are more filled with the thought of the possessions that others may take from them, than of the joy that they might create in their own lives and in the lives with which they come in contact. It is not so that life should be lived.

The pure mathematician, like the musician, is a free creator of his world of ordered beauty.

Do not use power to suppress opinions you think pernicious, for if you do the opinions will suppress you.