As pagan traditions started to dwindle in the face of the rising popularity of Christianity in the third and fourth century C.E., a new interpretation of ancient philosophy was born. Drawing from the cosmology of the Thimaeus, this tradition attempted to revive the writings of Plato for a new time. This was a world view which gave place not only to the gods of the classic Greek mythology but also to an interpretation of the transcendent monotheistic deity. This school of philosophy later became known as Neoplatonism.
With its roots in 2nd century Alexandria, Neoplatonism shares much of its cultural heritage with hermetism. Yet Neoplatonism's most famous proponent was not an Alexandrian, but instead came from Syria. His name was Iamblichus. Orating within a tradition that oftentimes had little interest in magical pursuits, Iamblchus became an important apologetic of esoteric practices. The writings of Iamblichus include a new definition of sacred magic dubbed Theurgy, or divine-working, which ought to sound familiar even to many new age practitioners today.
Neoplatonism came to an abrupt end in 529 A.D. when Emperor Justinian forced the Neoplatonist schools in Alexandria and Athens to close their doors. However, neoplatonist philosophy survived outside the Christian world, being openly adopted in the Islamic world and having a profound influence on the medieval Kabbalists. Together with the Hermetism, Neoplatonist philosophy was revived in Western Europe at the early days of the Renaissance and was again studied and adopted by the intellectuals of a new time.