The fourth century emperor Julian, remembered as the Apostate for abandoning the Christianity of his upbringing, was himself initiated into Mithraic worship and wrote a philosophical hymn, To King Helios, that draws the sun god and Mithras together in exactly the way the reliefs do, as distinct figures bound in a single divine reality rather than as two names for one thing. Julian's Mithras appears in the hymn as an intermediary power connecting the visible sun to a higher, intelligible sun beyond it, a role that gives philosophical shape to the handclasp and the shared banquet the reliefs show without literary explanation. Whether ordinary initiates two centuries earlier held anything as developed as Julian's scheme is unrecoverable, since nearly all Mithraic testimony below the rank of emperor is silent about doctrine, but the hymn shows that by the time the cult had an emperor as a member its imagery was capable of supporting a fully worked philosophical reading at the highest level of Roman intellectual culture. Julian's own religious program, an attempt to build pagan worship into something that could compete institutionally with the Christianity he had renounced, leaned on Mithraic solar theology as one of its resources, which makes the hymn evidence of the cult's late reception as much as of its content.