THESE volumes contain the Gifford Lectures delivered in the University of Glasgow in Sessions 1900-1 and 1901-2. I have, however, rewritten most of them, and have added three lectures upon parts of the subject which I was not able to discuss with sufficient fullness.
I have attempted, so far as was possible within the limits of such a course of lectures, to give an account of those ideas of Greek philosophy which have most powerfully affected the subsequent development of theological thought. In doing so, I have had to make a selection of topics which may require some explanation, both as to what it includes and as to what it excludes. On the one hand, I have thought it best to confine myself mainly to the most important writers, to Plato and Aristotle, to the chief representatives of the Stoic philosophy, and to Philo and Plotinus among the Neo-Platonists; and I have made no attempt to deal with secondary variations of opinion among the less important writers of the various schools. On the other hand, in regard to the philosophers of whom I have written more fully, I have dealt with many aspects of their thought which may not seem to bear directly upon theology. Thus I have treated at considerable length the question of the development of the Platonic philosophy in its logical and ethical as well as in its metaphysical and theological aspects. And though I have not gone quite so far in other cases, I have not hesitated to introduce a comparatively full account of the theoretical and practical philosophy of Aristotle and of the Stoics. It seemed to me quite impossible to show the real meaning of the theological speculations of these writers without tracing out their connexion with the other aspects of their philosophy. In the case of Plotinus I do not need to make any such statement; for theology is so obviously the centre of all his thought, that everything else has to be directly viewed in relation to it. In truth, however, this is only a matter of degree. A man's religion, if it is genuine, contains the summed-up and concentrated meaning of his whole life; and, indeed, it can have no value except in so far as it does so. And it is even more obvious that the theology of a philosopher is the ultimate outcome of his whole view of the universe, and particularly of his conception of the nature of man. It is, therefore, impossible to show the real effect and purport of the former without exhibiting very carefully and fully its relations to the latter.
I find it very difficult to trace out my obligations to the numerous writers on the subjects of which I have written. Of the books which I have recently studied, I owe most to Baümker's Das Problem der Materie in der Griechischen Philosophie, to Bonhöffer's Epictet und die Stoa, and to the account of Plotinus in von Hartmann's Geschichte der Metaphysik. I may also mention Whitaker's The Neo-Platonists, which contains a very careful and thorough account of the whole history and influence of Neo-Platonism.
I have been much assisted by the opportunity I have had of discussing various points with Professor Cook Wilson, with Professor Henry Jones, and with Mr. J. A. Smith of Balliol College.
Professor Jones and Mr. R. A. Duff of Glasgow University have read all the proofs of these volumes, and have made many suggestions which have been very useful to me.
The work of preparing an Index has been kindly undertaken by Mr. Hayward Porter.
OXFORD, November, 1903.