Arithmetic is a kind of knowledge in which the best natures should be trained, and which must not be given up.
PlatoSo the state founded on natural principles is wise as a whole in virtue of the knowledge inherent in its smallest constituent class, which exercises authority over the rest. And the smallest class is the one which naturally possesses that form of knowledge which alone of all others deserves the title of wisdom.
PlatoThat which is apprehended by intelligence and reason is always in the same state; but that which is conceived by opinion with the help of sensation and without reason, is always in a process of becoming and perishing and never really is.
Plato