Antisthenes also, in his book entitled The Natural Philosopher, says that while there are many gods of popular belief, there is one god in nature, so depriving divinity of all meaning or substance. Very similarly Speusippus, following his uncle Plato, and speaking of a certain force that governs all things and is endowed with life, does his best to root out the notion of deity from our minds altogether.
Source: Cicero in 28 Volumes. De Natura Deorum Academica. With English Translation by H. Rackham M.A. 1933. Internet Archive.