This book traces, for the first time, a revolution in philosophy which took place during the early centuries of our era. It reconstructs the philosophical basis of the Stoics' theory that fragments of an ancient and divine wisdom could be reconstructed from mythological traditions, and shows that Platonism was founded on an argument that Plato had himself achieved a full reconstruction of this wisdom, and that subsequent philosophies had only regressed once again in their attempts to'improve'on his achievement. The significance of this development is highlighted through parallel studies of the Hellenistic debate over the status of Jewish culture; and of the philosophical beginnings of Christianity, where the notions of'orthodoxy'and'heresy'in particular are shown to be tools in the construction of a unified history of Christian philosophy stretching back to primitive antiquity.