As for everything else, so for a mathematical theory: beauty can be perceived but not explained.
Arthur CayleyEuclid avoids it [the treatment of the infinite]; in modern mathematics it is systematically introduced, for only then is generality obtained.
Arthur CayleyAnd in another point of view, I think it is right that the address of a president should be on his own subject, and that different subjects should be thus brought in turn before the meetings.
Arthur Cayley