The theology which Augustine opposed to the errors of Pelagianism is, briefly, the theology of grace. The roots of this theology were deeply planted in his own experience and the teaching of Scripture, especially in the teaching of that apostle whom he delights to call “the great preacher of grace,” and to follow hard after whom was his great desire. The grace of God in Jesus Christ, conveyed to us by the Holy Spirit and evidenced by the love which He sheds abroad in our hearts, is the centre about which his whole system revolves.1 As over against the Pelagian exaltation of nature, he was never weary of glorifying grace. And this high conception the more naturally became the centre of his soteriology because of its harmony with the primal principle of his whole thinking, which was theocentric and grew out of his idea of God as the immanent and vitalizing spirit in whom all things live, and move, and have their being.2 That God is the absolute good, and nothing is good but God and what comes from Him, so that only as God makes them good may men do good, was the foundation-stone of all his theology. His doctrine of grace appears as but a specific application of this broad doctrine.
The necessity of grace Augustine argued from the condition of the race as sharers in Adam’s sin. God created man upright and endowed him with human faculties, including free will;3 and gave to him freely that grace by which he was able to retain his uprightness.4 Being thus put on probation,5 with divine aid to enable him to stand if he chose, Adam perversely used his free choice for sinning and involved his whole race in his fall. It was on account of this sin that he died spiritually and physically; and this double death passes over from him to us.6 That all his descendants by ordinary generation are partakers in Adam’s guilt and condemnation, Augustine is sure from the teachings of Scripture. This is the fact of original sin from which no one generated from Adam is free, and from which no one is freed save as regenerated in Christ.7 But how we are made partakers of it, he is less certain. Sometimes he speaks as if it came by some mysterious unity of the race, so that we were all personally present in the individual Adam and thus the whole race was the one man that sinned;8 sometimes he speaks more in the sense of modern realists, as if Adam’s sin corrupted the nature, and the nature now corrupts those to whom it is communicated;9 sometimes he speaks as if it were due to simple heredity.10 More characteristically he speaks as if it depended on the presence of shameful concupiscence in the act of procreation, so that the propagation of guilt depends on the propagation of offspring by means of concupiscence.11 However transmitted, it is yet a fact that sin is propagated, and all mankind became sinners in Adam. The result is that we have lost the divine image, though not in such a sense that no lineaments of it remain to us.12 And, the sinning soul making the flesh corruptible, our whole nature is corrupted, and we are unable to do anything of ourselves truly good.13
This corruption includes, of course, an injury to our will. Augustine, writing for the popular eye, treats this subject in popular language. But it is clear that in his thinking he distinguished between will as a faculty and will in a broader sense. As a mere faculty, will is and always remains an indifferent thing.14 After the fall, as before, it continues poised in indifferency, and ready, like a weathercock, to be turned whithersoever the breeze that blows from the heart (“will,” in the broader sense) may direct.15 It is not the faculty of willing, but the man who makes use of that faculty, that has suffered change from the fall. In paradise man stood in full ability. He had the posse non peccare, but not yet the non posse peccare;16 that is, he was endowed with a capacity for either part, and possessed the grace of God by which he was able to stand if he would, but also the power of free will by which he might fall if he would. By his fall he has suffered a change, is become corrupt, and has fallen under the power of Satan. His will (in the broader sense) is now injured, wounded, diseased, enslaved—although the faculty of will (in the narrow sense) remains indifferent. Augustine’s criticism of Pelagius’ discrimination17 of “capacity” (possibilitas, posse), “will” (voluntas, velle) and “act” (actio, esse), does not turn on the discrimination itself, but on the incongruity of placing the power, ability in the mere capacity or possibility, rather than in the living agent who “wills” and “acts.” He himself adopts an essentially similar distribution, with only this correction.18 He thus keeps the faculty of will indifferent, but places the power of using it in the active agent, man. According, then, to the character of the man, will the use of the free will be. If the man be holy he will make a holy use of it, and if he be corrupt he will make a sinful use of it; if he be essentially holy, he (like God Himself) cannot make a sinful use of his will; and if he be enslaved to sin, he cannot make a good use of it. The last is the present condition of men by nature. They have free will;19 the faculty by which they act remains in indifference, and they are allowed to use it just as they choose. But such as they cannot desire and therefore cannot choose anything but evil;20 and therefore they, and therefore their choice, and therefore their willing, is always evil and never good. They are thus the slaves of sin, which they obey; and while their free will avails for sinning, it does not avail for doing any good unless they be first freed by the grace of God. The superior depth of Augustine’s view and its essential harmony with fact are apparent; if “the will” be conceived as simply the whole man in the attitude of willing, it would seem to be immediately evident that, however abstractly free the “will” is, it is conditioned in all its action by the character of the willing agent: a bad man does not cease to be bad in the act of willing, and a good man remains good even in his acts of choice.