 Favorinus wrote "On the Kataleptic Fantasy" in which he is said to have denied the possibility of katalepsis, the key notion of Stoic epistemology.One of the speeches of Favorinus contains the oldest example of "psychomachia", suggesting that he may have invented the alegorical technique, which the Latin poet Prudentius later applied with so much success to the Christian soul resisting various kinds of temptation.Favorinus is described as a eunuch (εὐνοῦχος) by birth.