In the second half of this book the impact of Iamblichus' Pythagoreanizing programme on his successors was examined in regard to

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some influential members of the Platonic School at Athens. Use of Pythagorean literature in the philosophical curriculum can be observed in the case of Hierocles and elsewhere (see Appendix II). Syrianus knew Iamblichus' On Pythagoreanism and recommended it to his students. He shares Iamblichus' views on the nature and history of philosophy as the revelation of wisdom by the pure soul of Pythagoras, whose inspiration was followed especially by Plato and the Platonists and to some degree Aristotle. He finds thus in Aristotle's Metaphysics some truth concerning higher immaterial realities, but must correct Aristotle in terms of a theory of the nature of Pythagoreanism, the major source of which is Iamblichus. Syrianus' pupil Proclus shows similar tendencies, particularly in his early Commentary on the Timaeus, where he takes Plato's dialogue as expressing Pythagorean cosmology. However, Proclus also reacted critically to the Pythagoreanizing programme. He found the first scientific expression of truth, not (as Iamblichus had) among the ancient Pythagoreans, but in Plato's dialogues. In consequence Plato supplants Pythagoras as the central authority in Proclus' writings. Furthermore, although fully accepting the pivotal role played by mathematics in the philosophical sciences, Proclus modifies this role in various ways. Geometry, rather than arithmetic, is chosen as the pre-eminently mediatory mathematical science, on account of its discursive, demonstrative method. Proclus thus assimilates geometric to scientific method and gives to his philosophical work in physics and metaphysics a marked geometrical aspect. He also insists on the subordination of mathematics to the science of the divine, dialectic or theology, in such a way as to make clear the inadequacy of Pythagorean mathematical imagings of the divine. This requires, however, a definite concept of the science of the divine as supposedly communicated in Plato's writings, a concept that is largely inspired, both in regard to the method and contents of dialectic, by Proclus' view of the structure and contents of mathematics. The originality of these important features of Proclus' philosophy cannot, I believe, be adequately appreciated if no reference is made to their background as a reaction to Iamblichus' Pythagoreanizing programme.

In conclusion I would like to address a question that can scarcely be ignored: Why did Iamblichus seek to Pythagoreanize Platonic philosophy? Why did he attempt to reformulate this philosophy as the revelation of truth to the ancient Greeks by a divine soul? This question takes on greater importance if we suppose that it concerns

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not just the internal history of Greek philosophy but also the broader intellectual patterns of the period. Ought Iamblichus' project to be seen in the light of the political success and the increasing theoretical sophistication of another revealed truth, Christianity? Is Iamblichus' figure of Pythagoras the pagan response and counterpart to Christ?

Certainly the pagan philosophers of late Antiquity were very aware of the threat that Christianity represented for them. Already in the second century Celsus had attacked the pretensions of Christians that their religion was the ancient wisdom that had inspired Greek philosophers. Porphyry, who attacked under Plotinus' direction various gnostic sects, wrote a critique of Christianity that was all the more dangerous than Celsus's in that it was based on a superior philological, historical, and philosophical competence. Perhaps in Plotinus and certainly later in Proclus there are veiled references to Christianity. ⁷