Like ourselves , it took for granted that that world was intelligible .sx Like ourselves , too , it recognized that no individual object was intelligible by itself .sx The only possibility of knowing it was through its relations to other things .sx The mind , for instance , had the power of detecting those features which all the members of a particular group of things had in common and which were not shared by any individual outside that group .sx To distinguish those groups or kinds of things was a beginning of knowledge of the individual things comprised in each kind .sx But for the increase of such knowledge it was necessary that the process of mental separation or abstraction from the characteristics of individual objects should be carried further .sx Within the more general kinds it was possible to distinguish various subordinate classes , all the individuals of each class possessing , in addition to the characteristics of the more general kind , the specific difference peculiar to that class .sx Thus men and horses and elephants and a thousand other classes or species shared all the characteristics of the larger kind or genus , animal , while all the individuals of each class were characterized by the particular difference which made them into a single class .sx The specific difference of man , for instance , was reason .sx Man was a rational animal .sx In that definition , embracing the abstractions represented both by genus and species , you had a certain knowledge of every individual man , past , present or future .sx Now what is important is that what was thus known was conceived of as a reality , something actually existent in man and in each individual man .sx It was not a bare abstraction only , a mere figment of the mind .sx But again it had no existence of its own apart from things .sx It was not a Platonic idea .sx It existed only in things , and existed in them as the principle both of their intelligibility and of their existence .sx In this latter regard it was the form of the thing , the ordering principle or idea impressed upon a material substrate to make it just that particular thing .sx Thus each individual thing in the whole created order consisted of matter and form .sx But further , the created order was a world of continuous becoming , a constant process of generation and corruption .sx . Everything was capable of becoming something higher in the scale of being or of becoming more fully itself .sx Every existent composite of matter and form could thus become matter of ahigher or fuller form .sx Regarded as matter , it was the mere potentiality of a higher type of being which was actualized by the assumption or impress of the higher form .sx Now the importance of all this is its bearing upon the nature of our human knowledge .sx What we know does actually exist in things .sx Form and matter , potentiality and actuality , and the passing from one to the other , are actual elements in the becoming of all existence .sx And these phases of reality we can and do know by the mind's power of abstracting them from our sense-impressions .sx But they are all we know .sx The infinite depth and richness of the individual thing escapes us .sx If man is a rational creature , his intelligence is yet of the lowest order of intelligences .sx A perfect intelligence would not depend for its know-ledge upon the roundabout process of abstraction , with its very imperfect results .sx It would apprehend in a momentary intuition the wholeness of reality .sx Such knowledge was impossible for man just because he was not a pure intelligence like the angels , but an intelligence dependent upon body for all the materials of its knowledge .sx Yet man was constituted with an insatiable thirst for knowledge .sx He could never be satisfied with the only kind of knowledge which was possible for him here in via .sx Only the knowledge , the immediate vision , of the Divine Perfections could satisfy him , and for that knowledge all his life here must be a preparation .sx II .sx Such was the conception of man's nature to which the doctrine of Grace had to be fitted .sx That doctrine as shaped by St. Augustine was a corollary of the doctrine of the Fall .sx For the East , prior to Augustine , it seems as if the tragedy of the Fall had centred principally , if not altogether , in man's loss of immortality , while the redemptive work of Christ was mainly the re-conquest of immortality .sx Even St. Paul might be interpreted benignly in this sense .sx `As in Adam all die , even so in Christ shall all be made alive,' could be taken as governing his more uncompromising statements of the effects of Adam's sin .sx So , too , the gift of God , His free grace , was eternal life through Jesus Christ .sx Grace was almost a synonym for the whole Christian economy .sx As most fitly describing God's free gift of .sx newness of life through Jesus Christ , it was the natural antithesis of the Law which could only convict of sin and death .sx The economy of grace , of the new life with its almost natural dower of immortality , had so annulled the effects of the Fall that within its magic circle of renewing power man was henceforth able of himself to render true and in some sense even meritorious obedience to God .sx Christ had accomplished the work of redemption in the power of which the initiate were required to shape their own lives after His example .sx In some such circle of ideas Greek theology seemed to move , especially when , as in Chrysostom , it took on a mainly pastoral and practical character .sx Not Pelagius , but Augustine , was the innovator here .sx Augustine discovered St. Paul , or at least he discovered the St. Paul we know .sx After him , no one up till quite recent times attempted to read St. Paul without the aid of Augustinian glasses .sx And what Augustine discovered was that St. Paul had taken the Fall seriously , and that therefore his doctrine of grace had a religious depth and fulness of which Greek theology had at the best no more than a distant glimpse .sx Whether he had interpreted St. Paul aright is a question which we need not now discuss .sx What matters is that his interpretation became the classical doctrine of grace which the whole of later Western theology accepted as alone bearing the hall-mark of revealed truth .sx Later theological systematization might indeed entail certain changes which seemed to modify the stringency of its statement .sx But the doctrine itself was definitely beyond the reach of challenge or criticism .sx The root-conception of the Augustinian doctrine was the utter corruption of human nature which was the result of the Fall .sx As partakers in Adam's sin , all men were also sharers in his guilt .sx They were the born-thralls of sin , the predestined victims of God's avenging justice .sx They lay in the hell like sheep , incapable of one least movement even of desire for the Infinite Goodness which was yet the only satisfaction of their original created nature .sx From that universal impotence the free unmotived mercy of God rescued those whom He had predestined to everlasting life .sx Stated in this schematic fashion , the doctrine has not unnaturally seemed rather an indictment than a justification of the Divine Goodness .sx Someone has describedthe theology of Karl Barth as the `theological form of atheism .sx ' It is easy enough , I think , to see what is meant , and to see also how every Augustinian `dialectic' of grace may lie open to the same condemnation .sx But this is not the way to do justice to a doctrine which in one way or another has been the nerve of almost every great revival of religious feeling throughout Christian history .sx Not only its value but its very meaning must be sought within those moments of feeling , and especially within the moment which first gave it birth .sx The anti-Pelagian treatises of Augustine must be read in the light of his Confessions .sx The theologian must be interpreted through the saint .sx And here , as always , the saint is just the man who recognizes himself both as a sinner and as one who is being continuously rescued by a Power not himself from his sin .sx It is unnecessary here to elaborate the doctrine which St. Augustine in the light of that experience found in the teaching of St. Paul .sx We shall have occasion presently to consider some of its details as utilized by the mediaeval theologian .sx For the moment it will be sufficient to call attention to two points at which the Thomist theology diverges from its Augustinian heritage .sx For Augustine grace is the restoration of man's true nature .sx That nature had been sufficient to the true knowledge and the adequate service of God .sx The Fall had so vitiated that nature that it could neither know God nor serve Him unless and until the free act of His grace had restored its original power .sx And , secondly , the Augustinian theory of knowledge required for its effective exercise purification of spirit .sx Truth was apprehended only in virtue of a direct divine illumination of the human intellect .sx It was only in God , as that great seventeenth century Augustinian Malebranche put it , that we could perceive the truth of things .sx And as the intellect had suffered from the debilitating effects of the Fall , it was only grace that could restore that irradiation of the soul by the Sun of Truth on which all its real knowledge depended .sx There was nothing on which the Augustinians of the twelfth and early thirteenth centuries , from Anselm to Bonaventure , were more agreed than on this , that all knowledge depended on purity of spirit .sx Now St. Thomas no more than anyone else who accepted the Christian Revelation denied that the Fall had weakened .sx man's intellectual power .sx Reason was inevitably obscured by the mists of inordinate passions and affections .sx But it had been weakened only , not radically injured .sx Besides , the Christian Aristotelians had an entirely different theory of knowledge .sx They rejected altogether the Neoplatonic and Augustinian intuitionism .sx For them all human knowledge was derived from the data of sense-perception .sx The knowing subject was not for them , as for the Platonist , a mind imprisoned in a body , but a mind informing a body and using it as a medium .sx But just because the mind was thus allied to body its reach was limited .sx It was not equal to the satisfaction of its native desire for the apprehension of absolute reality , for the attainment of ultimate truth .sx Yet that was its desire , and the satisfaction of it its blessedness .sx It could indeed of its own power , by the use of the first principles of reason with which it was endowed , the principles of contradiction and identity , of sufficient reason and the like , ascend from sense-data to a certainty of the Divine existence , even to a knowledge at least analogical of the Divine attributes .sx But the Divine essence , the inner mystery of the Divine nature , it could never know .sx Yet God had not left the desire for even that knowledge altogether unsatisfied .sx He had revealed it revealed it , that is to say , so far as it could be revealed to the incorporate human intelligence through such distant analogies as those by which the natural reason had already apprehended the Divine attributes .sx Thus Reason and Revelation represented the two grades of knowledge by means of which man could prepare himself here for that immediate vision of the Perfect Truth to which he could only fully attain hereafter .sx Now to these two orders of knowledge , the naturally acquired and the revealed , there corresponded two orders in which man's whole life was set , the natural and the supernatural , the order of nature and the order of grace .sx The order of nature was the created order as it was shaped by the creative thought of God .sx But whereas man's share in that nature was conceived by St. Augustine as sufficient for the achievement of eternal blessedness , St. Thomas held that it had no such sufficiency .sx If man had never fallen , he would still have needed the help of grace to attain his true end of blessedness .sx While therefore for .sx Augustine the Fall was the total corruption of a perfect nature , it was for Aquinas at most the weakening of a nature which was of its very essence imperfect , which had always needed another order of nature to supplement and complete it .sx