Charles Sanders Peirce Quote

Mathematics is distinguished from all other sciences except only ethics, in standing in no need of ethics. Every other science, even logic, especially in its early stages, is in danger of evaporating into airy nothingness, degenerating, as the Germans say, into an arachnoid film, spun from the stuff that dreams are made of. There is no such danger for pure mathematics; for that is precisely what mathematics ought to be.

Collected Papers of Charles Sanders Peirce (ed. Harvard University Press, 1933) - ISBN: 9780674138018