" DEMOCRITUS made it consist in motion, consequently gave it a manner of existence. ARISTOXENES, who was himself a musician, made it harmony. ARISTOTLE regarded the soul as the moving faculty, upon which depended the motion of living bodies. The earliest doctors of Christianity had no other idea of the soul, than that it was material. TERTULLIAN, ARNOBIUS, CLEMENT of ALEXANDRIA, ORIGEN, SAINT JUSTIN, IRENAEUS, have all of them discoursed upon it; but have never spoken of it other than as a corporeal substance—as matter. "

― Denis Diderot , System of Nature