 The coherence stems from his interpretation of ancient learning. From, principally, the fifteenth-century Christian Platonist Marsilio Ficino, he learned of the gentile tradition of wisdom, the “ancient philosophy”, that had allegedly originated with sages such as Zoroaster in Persia and Hermes Trismegistus in Egypt. Orpheus, Pythagoras and other early Greek thinkers had imbibed this wisdom and transmitted it to Plato, among many others. Through innate powers of mind, divine inspiration or direct or indirect knowledge of Jewish lore, these sages and philosophers had acquired intimations of many, indeed most, of the essential tenets of Christianity. Hence, concluded Ficino, the study of ancient Greek philosophy, especially Platonism, could rightfully serve as a handmaiden to the Christian faith. Bruno denied any such notions of progress. Human knowledge, like all natural things, observed the rule of vicissitude (see  Section 3), gradually oscillating from one extreme to the other. Greek philosophy from Plato onwards was a debased version of the true wisdom known to ancient sages such as Hermes Trismegistus among the Egyptians and Pythagoras, Parmenides and Empedocles among the early Greeks. The task, then, was to restore an authentic ancient philosophy by elaborating upon what could be discerned in the few surviving Egyptian and Pythagorean records of it with the help of vestigial truths preserved in Greek philosophy. Even Aristotle, “the stupidest of all philosophers”, who had done his best to “pervert the opinions of the ancients and oppose the truth” (BOI I, 182, 730), sometimes included, despite himself, valuable ideas gleaned from his predecessors. The many other philosophical sources that Bruno eclectically pressed into service—Presocratic, Platonic, Aristotelian, Stoic, Epicurean, medieval, Arabic, scholastic and Renaissance—had the same purpose: the articulation of a philosophy true to the principles of an ancient wisdom all but obliterated by Aristotle and his followers.