Cicero, De Natura Deorum, Lib. I. 27:  “Pythagoras thought that God was the soul pervading all nature.”  The doctrine was accepted both by Stoics and Platonists, and became very general.  Cf. Virg. Georg. iv. 221: Deum namque ire per omnis Terrasque, tractusque maris, cælumque profundum. and Æn. vi. 726: Spiritus intus alit, totamque infusa per artus Meus agitat molem, et magno se corpore miscet.