It has long been established that Philo's account of the Greek translation of the Pentateuch is based upon the Letter of Aristeas. Less clear, however, is how Philo regarded Aristeas' account. Had it become the authoritative origin story for the LXX in the Alexandrian community, or was it simply Philo's preferred version of events for rhetorical purposes? If Philo did consider Aristeas' story to be history, why did he so severely change the account on the crucial matter of the process of translation? This paper attempts to solve the problem of the relationship between these texts by comparing Philo's use of Aristeas to his use of Biblical texts, which Philo undoubtedly held to be authoritative scripture. It will be demonstrated that, though Aristeas was likely not scripture for Philo, his attitude toward adaptation and revision is perfectly in line with his treatment of scripture.