Mathematics is, I believe, the chief source of the belief in eternal and exact truth, as well as the super-sensible intelligible world. Geometry deals with exact circles, but no sensible object is exactly circular; however carefully we may use our compasses, there will be some imperfections and irregularities. This suggests the view that all exact reasoning applies to ideal as opposed to sensible objects; it is natural to go further and to argue that thought is nobler than sense, and the objects of thought are more real than those of sense-perception.
— Bertrand Russell 'The History Of Western Philosophy' (pp55-6)
