Of Agrippa Castor we know only what Eusebius tells us here. Jerome (de vir. ill. chap. 21) adds nothing new, and Theodoret’s statement (Fab. I. 4), that Agrippa wrote against Basilides’ son, Isidore, as well as against Basilides himself, is simply an expansion of Eusebius’ account, and does not imply the existence of another work. Agrippa’s production, of which we do not know even the title, has entirely disappeared.