In the foregoing remarks we have already passed from the purely aesthetic to the historical or psychological view of Neo-Platonism—that is, the view which considers a philosophy in reference to the circumstances of its origin. Every speculative system reflects, more or less fully, the spirit of the age in which it was born; and the absence of all allusion to contemporary events does not prove that the system of Plotinus was an exception to this rule. It only proves that the tendency of the age was to carry away men’s thoughts from practical to theoretical interests. We have already characterised the first centuries of Roman imperialism as a period of ever-increasing religious reaction; and in this reaction we attempted to distinguish between the development of supernaturalist beliefs which were native to Greece and Italy, and the importation of beliefs which had originated in the East. We saw also how philosophy shared in the general tendency, how it became theological and spiritualistic instead of ethical and naturalistic, how its professors were converted from opponents into upholders of the popular belief. Now, according to some critics, Neo-Platonism marks another stage in the gradual substitution of faith for reason, of authority for independent thought; the only question being whether we should interpret it as a product of Oriental mysticism, or as a simple sequence of the same movement which had previously led from Cicero to Seneca, from Seneca to Epictêtus, from Epictêtus to Marcus Aurelius. Of these views, the first is taken by Ritter, and adopted with some modifications by M. Vacherot in his _Histoire de l’École d’Alexandrie_. It is also unreservedly accepted by Donaldson in his continuation of Müller’s _History of Greek Literature_, and is probably held at this moment by most Englishmen who take any interest in the subject at all. The second view—according to which Neo-Platonism is, at least in its main features, a characteristic although degenerate product of Greek thought—is that maintained by Zeller. As against the Orientalising theory, it seems to us that Zeller has thoroughly proved his case.[506] It may be doubted whether there is a single idea in Plotinus which can be shown to have its exact counterpart in any of the Hindoo or other Asiatic systems whence he is supposed to have drawn; and, as our own analysis has abundantly shown, he says nothing that cannot be derived, either directly or by a simple and easy process of evolution, from Plato, Aristotle, and the Stoics. On the other hand, has not Zeller gone much too far in treating Neo-Platonism as a product of the great religious reaction which unquestionably preceded and accompanied its appearance? Has he not altogether underrated its importance as a purely speculative system, an effort towards the attainment of absolute truth by the simple exercise of human reason? It seems to us that he has, and we shall offer some grounds for venturing to differ from his opinion.