The Instructions of Commodianus 15

Hercules, because he destroyed the monster of the Aventine Mount, who had been wont to steal the herds of Evander, is a god: the rustic mind of men, untaught also, when they wished to return thanks instead of praise to the absent thunderer, senselessly vowed victims as to a god to be besought, they made milky altars as a memorial to themselves. Thence it arises that he is worshipped in the ancient manner. But he is no god, although he was strong in arms.