Pythagoreans, the school of philosophy founded by Pythagoras, "the fundamental thought of which," according to Schwegler, "was that of proportion and harmony, and this idea is to them as well the principle of practical life, as the supreme law of the universe." It was a kind of "arithmetical mysticism, and the leading thought was that law, order, and agreement obtain in the affairs of Nature, and that these relations are capable of being expressed in number and in measure." The whole tendency of the Pythagoreans, in a practical aspect, was ascetic, and aimed only at a rigid castigation of the moral principle in order thereby to ensure the emancipation of the soul from its mortal prison-house and its transmigration into a nobler form. It is with the doctrine of the transmigration of souls that the Pythagorean philosophy is specially associated.