Since the antique and patristic constituted well-nigh the whole substance of philosophy and theology in the Middle Ages, a separate consideration of what was thus transmitted would amount to a history of mediaeval thought from a somewhat unilluminating point of view. On the other hand, one may learn much as to the qualities of mediaeval thought from observing the attitudes of various men in successive centuries toward Greek philosophy and patristic theology. The Fathers had used the concepts of the former in the construction of their systems of acceptance of the Christian Faith. But the spirit of inquiry from which Greek philosophy had sprung, was very different from the spirit in which the Fathers used its concepts and arguments, in order to substantiate what they accepted on the authority of Scripture and tradition. It is true that Greek philosophy in the Neo-Platonism of Porphyry and Iamblicus was not far from the patristic attitude toward knowledge. But the spirit of these declining moods of Neo-Platonism was not the spirit which had carried the philosophy of the Greeks to its intellectual culmination in Plato and Aristotle, and to its attainment of the ethically rational in Stoicism and the system of Epicurus. Thus patristic thinking was essentially different in purpose and method from the philosophy which it forced to serve its uses; and the two differed by every difference of method, spirit, and intent which were destined to appear among the various kinds of mediaeval thinkers. But the difference between Greek philosopher and Church Father was deeper than any that ever could exist among mediaeval men. Some of the last might be conventionally orthodox and passionately pious, while others cared more distinctly for the fruits of knowledge. But even these could not be as Greek philosophers, because they were accustomed to rely on authority, and because they who drew their knowledge from an existing store would not have the independence and originality distinguishing the Greeks, who had created so much of that store from which they drew.[423] Moreover, while neither Plato’s inquiry for truth, nor Aristotle’s catholic search for knowledge, was isolated from its bearing on either the conduct or the event of life, nevertheless with them rational inquiry was a final motive representing in itself that which was most divinely human, and so the best for man.[424] But with the philosophers of the Middle Ages, it never was quite so. For the need of salvation had worked in men’s blood for generations. And salvation, man’s highest good, did not consist in humanly-attained knowledge or in virtue won by human strength; but was divinely mediated and had to be accepted upon authority. Hence, even in the great twelfth and thirteenth centuries, intellectual inquiry was never unlimbered from bands of deference, nor ever quite dispassionately rational or unaffected by the mortal need to attain a salvation which was