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]


  1. ^ Diogenes Laërtius, vii. 143
  2. ^ a b Diogenes Laërtius, vii. 148
  3. ^ Philo, De aeternitate mundi 76–77
  4. ^ Diogenes Laërtius, vii. 149
  5. ^ Geminus, xvii 48