The roots of the Christian philosophical tradition can be traced back to the Jewish Middle Platonist, Philo of Alexandria (c.25 BCE-50 CE).1 Philo was the first extant Jewish writer to unite hellenistic philosophy with Judaism,2 reconciling the impersonal divine principle of Platonism with the personal God of the Hebrew Scriptures. Nearly a century later, Tatian’s teacher, Justin Martyr, presented a Christian philosophy that also drew on the Middle Platonic tradition. If, as has been suggested,3 some sort of relationship exists between the Platonism of Justin and that of Philo, then it may be that in Tatian we encounter a developing Christian philosophical tradition, inherited from his master. What I intend to do in this chapter is to explore the roots of Tatian’s philosophical tradition in both Philo and Justin, and to examine Tatian’s presentation of that tradition in his Oration.