Boethus ( Greek: Βοηθός; fl. 2nd century BC) was a Stoic philosopher from Sidon, and a pupil of Diogenes of Babylon.
He is said to have denied, contrary to the standard Stoic view, that the cosmos is an animate being, [1] and he suggested that it was not the whole world which was divine, but only the ether or sphere of the fixed stars. [2] He argued that the world was eternal, [3] in particular, he rejected the Stoic conflagration ( ekpyrosis) because god or the World-Soul would be inactive during it, whereas it exercises Divine Providence in the actual world.
Among his works was one On Nature, [2] and one On Fate. [4] He wrote a commentary on the works of Aratus in at least four volumes. [5]