As for everything else, so for a mathematical theory: beauty can be perceived but not explained.
Arthur CayleyMetrical geometry is thus a part of descriptive geometry, and descriptive geometry is all geometry.
Arthur CayleyNot that the propositions of geometry are only approximately true, but that they remain absolutely true in regard to that Euclidean space which has been so long regarded as being the physical space of our experience.
Arthur CayleySo much the worse, it may be, for a particular meeting: but the meeting is the individual, which on evolution principles, must be sacrificed for the development of the race.
Arthur Cayley