The pre-Socratic philosophy took its stand on natural science, to the exclusion of ethics and religion.
Heidel, " The Logic of the Pre-Socratic Philosophy," in Dewey's Studies in Logical Theory (Chicago, 1903).
Other names of the pre-Socratic and Socratic times are mentioned by Xenophon, Plato and Aristotle.
Zeller, Pre-Socratic Philosophy (Eng.
In the case of Pythagoras, conspicuous among pre-Socratic philosophers as the founder not merely of a school, but of a sect or order bound by a common rule of life, there is a closer connexion between moral and metaphysical speculation.