The horses that draw the chariot of Achilles are energized by the menos ‘mental power’ that Zeus literally breathes into them. Their animal mentality can now enable them to perform physically what they need to do, which is, to draw the chariot of Achilles away from danger. In other contexts, heroes are energized by the menos ‘mental power’ that gods breathe into them, and such an enhanced human mentality enables them to perform physically their heroic deeds. See the comments on I.10.482, I.11.508, I.12.018, I.15.059–060, I.15.262.