An Introduction to the Work of Augustine

Augustine’s thought is broad and covers topics in theology, philosophy, and politics.


Despite typically being classified as a Christian theologian and philosopher, Augustine did not convert to Christianity until his thirties, spending much of his earlier life engaged in the study of classical Greek and Roman thought as well as the Neoplatonist school that had, more recently, emerged from it. Augustine describes his encounter with Neoplatonism as turning him away from materialism and introducing him to the idea that the world can be divided into two realms: the sensible-material and the intelligible-spiritual (Confessions 7.10). Drawing heavily on the original Platonic doctrine of the Ideas or the Forms, Neoplatonism holds that the material world, observable through the human senses, constitutes only a pale, fragmented reflection of the highest and truest form of reality. The spiritual-intelligible world contains, at its center, the One, the original source and first cause of all being. The One may also be called the Good, as it is held to be responsible for instilling purpose and order throughout the material world. Even prior to its encounter with Christianity, Neoplatonism contained certain religious or mystical elements: it was believed that the soul was immortal and that, after the death of the earthly body, the soul continues to exist in the spiritual realm, at a predetermined distance from the One corresponding to the relative goodness of its earthly life. The best way of life, Neoplatonism contends, is the life of philosophic contemplation, which promises perfect happiness in the material world and, later, a secure place in the highest regions of the spiritual world.

For Augustine, the One was embodied by God, the unifying source of all being, order, and goodness in both the material and the spiritual world. The bridge between the two worlds, however, was not philosophic contemplation, as Plato and Neoplatonism each suggested, but, rather, dutiful devotion to God. In addition, Augustine rejected the Neoplatonist notion that there existed any perfect happiness in the material world that human beings could enjoy if they led their lives in the appropriate manner. Instead, the material world was forever tainted by the allure of bodily temptations and the inescapable finality of earthly existence. According to Augustine’s understanding of original sin, human moral responsibility is meaningfully preserved despite original sin since the soul remains capable, if properly educated, of redirecting its attention toward God and the spiritual realm over which he presides. Goodness consists in the proper assignment of relative value to material and spiritual goods. Original sin can thus be understood in terms of mistaken perception, and is of intellectual rather than bodily origin (City of God 13.14-15).

Just War Theory

The Christian political doctrine of just war is first discussed explicitly by Augustine, before finding its most famous articulation almost nine hundred years later in Aquinas’ Summa Theologiae. Augustine first confronts the question of whether war can be divinely sanctioned in the context of defending the continuity of the Old Testament with the New Testament against his frequent scholarly opponent, the Manicheans. In defense of the wars of the Israelites and, more boldly, Abraham’s binding of Isaac, Augustine distinguishes between the act, the agent, and the authority that governs the action. In Against Faustus, he claims that divine authorization can render an otherwise contemptible agent or act praiseworthy, provided it is motivated by faithful submission. As to the spirit in which war ought to be waged, Augustine is insistent that it be punitive, rather than preventive or defensive.

Augustine’s emphasis on the authorization of violence extends to earthly political rule as well. A just war must be punitive, not preventive or defensive, and undertaken on behalf of a lawful authority. As citizens, men may wage just war in the service of their country, but, as individuals, they are not justified in engaging in civil resistance, even if their country is the source of an injustice. In defense of deference to political authority, Augustine writes: “…the natural order which seeks the peace of mankind ordains that the monarch should have the power of undertaking war if he thinks it advisable, and that the soldiers should perform their military duties on behalf of the peace and safety of the community” (Against Faustus). Even where an “ungodly king” issues an “unrighteous command,” the soldier retains his innocence because “his position makes obedience a duty.” When legitimate authorization cannot be found for violence (as with civic unrest), Augustine encourages a spirit of patient endurance on the part of those who suffer. Their primary concern ought to be correcting and converting the one who causes the suffering.

Nonetheless, Augustine acknowledges that “when we are trying to make unwilling souls yield…we often have to act with a sort of kindly harshness…because we have to consider their welfare rather than their inclination” (Letter to Marcellinus). The goal of any attempt at correction, whether or not it involves violence, is peace, understood as the restoration of an earthly order analogous to the perfectly ordered peacefulness of the kingdom of heaven. Without the worldly burden of sin, “it will not be necessary that reason should rule vices which no longer exist but God shall rule the man, and the soul shall rule the body, with a sweetness and facility suitable to the felicity of a life which is done with bondage” (City of God 19.27).

The Soul

As Augustine thought the world to be divided into two halves, the material and the spiritual, so, too, did he consider man to be a composite being, divided into the body and the soul. It is the province of the immaterial and immortal soul to rule over the body (De Animae Quantitate 13.22). Augustine derives the supremacy of the soul over the body from the broader hierarchical classification of beings into those that exist, those that exist and live, and those that exist, live, and reason (De Libero Arbitrio 2.3). Since man’s faculty of reason exists within his soul, it follows that the soul enjoys a higher position than does the body. As a result, the soul is not inescapably trapped by the body, and it is possible for man to reject the temptations of this world in favor of true happiness in the next. In addition to our capacity for reason and sense perception, we also possess what Augustine calls an inner sense. Positioned somewhere between the senses and reason, the inner sense serves to collect all of the sensory data from each of the senses and combine it into a single, coherent perception (De Libero Arbitrio 2.3).

In addition, the inner sense can recognize when the sensory data it receives cannot be united. The inner sense, therefore, possesses a capacity for judgment that it shares with reason. Unlike the inner sense, however, reason does not rely on sensory data from an external world in order to function. Instead, reason consists of the ability to engage in deductive thinking, to recognize the logic of necessity when it is present, and to conclude, on the basis of logical necessity, that certain absolute truths exist (De Libero Arbitrio 2.8). There is much, Augustine argues, that human beings cannot verify and must trust on the basis of authority (De Magistro 11.37). The implications of the existence of such necessary uncertainty must be considered, however, in light of the fact that the ultimate authority and source of truth is understood to be God, whose goodness and wisdom Augustine considered to be unquestionable.

Free Will and Divine Grace

The centrality of rational thought and moral responsibility in Augustine’s thought challenges the Christian conception of godly omniscience, which suggests an element of predestination in all human action. Similarly, the arguments made, at times, by Augustine concerning the need for deference to authority appear in tension with his elevation of individual free thought. In part, these difficulties can be explained by the intellectual transformation that Augustine underwent as he became increasingly immersed in Christian theology. Augustine makes the case for reason and free will most strongly during the period of his life when he was most influenced by Neoplatonism. Augustine’s shifting understanding of the will also appears to have been strongly influenced by his dispute with the Pelagians, a group of Christian theologians and scholars who downplayed the severity and significance of original sin, apparently in order to reduce man’s reliance on divine grace for redemption.

Partially in response to the controversy surrounding the Pelagians, Augustine eventually argues that original sin renders human redemption universally and absolutely impossible in the absence of divine grace. This argument is accompanied by a similar one that supports the doctrine of predestination, such that God has always known that man is incapable of saving himself (City of God 14). Instead of abandoning his earlier embrace of free will entirely, however, Augustine concludes that man remains morally responsible for his actions even as he is free only to sin (City of God 21.12). Ultimately, Augustine finds little room for human hopefulness. Although not all men are irredeemable, those few who find themselves saved are not such because of any action of their own, but because they belong to a select group of predetermined individuals upon whom God chose to bestow his redeeming grace (City of God 21.12).

For further introductory reading, see:

St. Augustine” in The History of Political Philosophy, Eds. Leo Strauss and Joseph Cropsey, Chicago: 1987.

The Cambridge Companion to Augustine, Eds. Eleonore Stump & Norman Kretzmann, New York: 2001.