RPM, Volume 11, Number 21, May 24 to May 30 2009

The Doctrine of Original Sin

A Comparison of
Augustine, Pelagius, and Aquinas

By Jeremy T. Alder

Table of Contents



Pelagius Aquinas Comparison of Views




The doctrine of original sin is a question of both anthropology and soteriology. It is an important doctrine because it sets the playing field on which man stands before God. If the fall of man has little impact on his original state, then the work of redemption is less significant; but if original sin has had great impact on the original state of man, then the work of Christ in redemption will have much more significance for humanity. Similarly, if the fall of Adam has caused little or no damage to man, then grace has little or no importance; but if man has been greatly damaged by the fall, then grace is of great importance. The focus of this paper is to discuss the views of St. Augustine, Pelagius, and St. Aquinas on this great doctrine of original sin. The discussion will unfold the state of man prior to the fall and then the effects of the fall on mankind. The differences of these views will then follow this discussion.


Introduction Augustine was a man who struggled with himself. It is said that Romans, chapter seven, is a picture of his life. He was born on November 13, 354 in a small town in the Roman province of Numidia called Tageste in North Africa. His mother, Monica, was a devout Christian and his father Patricius was an official in the Roman Administration who became a Christian later in life (Hutchins, v). When Augustine was nineteen, he discovered philosophy. He was resolved to pursue truth wherever he could. He attempted to find truth in Manichaenism, which has the basic idea of a radical dualism—good/evil. This helped him understand his sin. Then he became disenchanted by Manichaenism and got involved with a group called the Academics or scheptics, which taught that truth could never be known. Also, he discovered Neoplatonism from the teachings of Plotinus. This was a turning point in his life because he was encouraged by Plotinus to read the Bible, which paved the road for his embracing of Christianity.

Man Before the Fall

Augustine believed that God is the creator of all things and that all things were created "good." God created woman out of the man so that the whole human race would spring out of the one man (Augustine, City of God, Page 502). Man, having a human soul was made in God's image. Man having a soul gave him a mind with intelligence and reason, which placed him in a position that surpassed all other creatures. Man in the garden was a recipient of God's grace and therefore could know God intimately because his mind was not clouded with sin. Man's will was both free and good and served God willingly with satisfaction and joy. For Augustine writes in The City of God, "The choice of the will, then, is genuinely free only when it is not subservient to faults and sins. God gave it true freedom, and now that it has been lost, through its own fault, it can be restored only by him who had the power to give it at the beginning" (Augustine, Page 569). Augustine taught that man had the posse peccare (meaning the ability to sin) and the posse non peccare (meaning the ability not to sin). He spoke of a "first grace" given to man called adjutorium, which assisted Adam to continue in his original non-fallen state, but it did not force him to not sin (Sproul, Page 52). Only in heaven will man be non posse peccare (meaning not possible to sin).

Adam had not only the possibility to not sin, but he could not sin easily. Man had a bent on doing good; he had a positive tendency to obey God and do good, and yet at the same time he possessed the possibility of sinning. Adam had to overcome his tendency or bent on doing good to disobey God (Sproul, Page 53).

God gave man his soul by either breathing on or implanting it in him. Then, God took the bone of Adam to create his wife to allow man to have children (Augustine, Pages 503-504). Augustine describes mankind as, "…man was created as one individual; but he was not left alone. For the human race is, more than any other species, at once social by nature and quarrelsome by perversion" (Augustine, Page 508).

The Effects of the Fall

God created man to be obedient and if he was loyal, man would have received immortality and bliss without the possibility of death; but if man was disobedient, God's just condemnation was the punishment of death (Augustine, Page 510). Death of the soul is different from that of the body. Death of the body occurs when the soul departs; death of the soul occurs when God abandons it. The body is mortal and will not live forever, but the soul is immortal because it never stops living and feeling (Ibid.).

Man was created upright, but God is not responsible for man's defect. Augustine held the view that the whole human race was involved in the original sin. He writes in his "Confessions," that he was struck with illness which all but carried him off to hell loaded with all the evil he committed against God, himself, and others and a host of other offenses over and above the bond of original sin, "by which we all have died with Adam" (Augustine, Pages 101-102). Augustine described humanity as a "mass of perdition." After the fall man had lost his ability to not sin and was non posse non peccare, meaning not possible to not sin.

Adam's fall affected all of his descendants. Augustine saw a link between sin and death. When man was created, man had the ability not to die and the ability to die. Adam would have continued to live if he would not have sinned. Life or death was the consequence of his response to God's commands regarding to not eat of the fruit. After Adam ate of the fruit, death passed on to all men, and part of the original sin is that fallen man has the inability to not die. Augustine refers to Romans 5:12 in The Enchiridion to show the organic unity of the whole human race and corporate solidarity with Adam (Sproul, Page 54).

Augustine believed that there is both a spiritual and physical connection between Adam and the rest of mankind. Man is spiritually connected to Adam in that we are joined to him as our representative. Man is physically connected to Adam in that the fall affected his body including his seed. All of mankind was in Adam's body when he sinned; he called this connection "in the loins of Adam" (James, Lecture 12).

Augustine, according to Philip Schaff, gives us eight consequences that resulted from Adam's sin in the garden. They are the fall itself, the loss of freedom, the obstruction of knowledge, the loss of God's grace, the loss of paradise, the presence of concupiscence, physical death, and hereditary guilt (Sproul, Page 56).

The fall itself is a consequence of the fall. Adam had the ability to not sin, but he also had he ability to sin. Adam was created good, but not immutably so; and this fall of Adam was very caustic because, at the height of his original condition, he sins and falls to the depths of depravity and moral decay.

The effect of the fall was loss of man's freedom of his will. Man was originally created with the inclination or tendencies to do good and obey God. Man had the position to be able to not sin, yet after the fall, man lost his freedom to obey God and all he can do is sin. Adam's positive inclination towards good was lost and was replaced with the inclination towards evil. He is only "free" to do evil and is incapable of doing good. His will, which was aided by grace, was to be used for good, but is now a source for evil.

The obstruction of knowledge has to do with man's ability to know God. Man's capacity for knowledge was far greater in creation than after the fall. This consequence of the fall is what is called the "noetic effects of sin" (or the effects of sin on the mind). The mind could understand and analyze truth correctly, now man's mind is tainted by sin. Man can still understand, reason, think, and use the faculty of the mind, but it is now tainted with the cancer of sin.

The loss of God's grace was a consequence of the fall and man lost his ability to obey God. The result is that God removed this grace from man and has "given them over" to their own sinful desires and wrong thinking. The heart is only evil all the time (Genesis 6:5), yet God's grace is demonstrated through sin's restraint of the law and His common grace.

The loss of paradise resulted when God removed the man and woman from the garden and all their comfort. The exile was not only difficult because they were removed from God's immediate presence, but then the curse on creation would make work hard and life painful. The ground was not only cursed, but so were the man and the woman with their consequences being passed on to all their posterity.

The presence of concupiscence is seen in man's pursuit of pleasure or sensuality. Man prefers the sensual life rather than the spiritual life. Humanity has a "bent" or "inclination" towards the lusts of the flesh. In the garden, the body was obedient to God, but after the fall the body was inclined towards sensual pleasure.

Physical death is a consequence of the fall. Originally, man had the ability to not die and the ability to die, but after the fall, man moved closer and closer to death each day. Original sin has brought all humanity face-to-face with the certainty of death.

And lastly, hereditary guilt is a consequence of the fall. This means that the condition of Adam after the fall is now passed on to all those who descend from him. All men have a sinful nature—a predisposition to sin. Man has no freedom to obey God in his natural condition; he is inclined toward evil unless the grace of God reverses the effects of the fall. All actual sin that man commits is based in or grounded in the fallen nature. In three ways man is guilty in a legal sense of Adam's sin because we have fallen short of God's holy standard. First, man is guilty because his representative has rebelled against God. Secondly, man is guilty because all of humanity is organically connected to Adam, meaning that we played a role in the fall and were in some sense present at the fall in Adam through whom we participated. And thirdly, man is guilty because man continues to commit sin, which demonstrates the sinful nature that has been passed down to us from Adam (James, Lecture 12).

Not only did Augustine teach that the entire human race was involved in the fall, but he taught that the first sin was pride. He writes, "Now could anything but pride have been the start of the evil will? For pride is the start of every kind of sin (Augustine, Page 571).

He taught that men were born sinners and that even infants share in the sinful nature and are sinful before they have committed any sin of themselves. This is why he applied baptism to infants for the remedy of the removal of their sin (Geisler, Page 117).


Introduction Pelagius was born in Britain in the year 354. He became a monk and lived in Rome where he converted Celestius who developed Pelagius' views. He was declared a heretic and was excommunicated from the church at the Council of Carthage in 416 with the support of Pope Innocent I. After Pope Innocent I died, Pelagius wrote a letter to the new Pope Zosimus, who wrote an encyclical stating that Pelagius' teaching were orthodox. Then the views of Pelagius were condemned at a second Council of Carthage in 418 (Sproul, Page 35).

Man Before the Fall

Pelagius taught that Adam was created good, for everything God created was good. He rooted his view of the nature of man and his free will in his doctrine of creation. Man was created sinless and had a moral neutrality. He was neither predisposed nor inclined toward good or evil. The will of man is unchangeable, meaning that it will not undergo change even after it sins. Pelagius believed that there is no inherent corruption in man (Sproul, Page 36). A person's behavior may change and be sinful, but his inherent nature has not changed.

Pelagius was directed by the principle that God would never command what was impossible for man to do. If God commands that we obey Him, then we must have the ability to obey. His perspective of man started with his natural ability of free will. Free will, in the fullest sense of the word, means that man can chose to do good or do evil. Man was created with an equal ability at every moment to do good or evil. The choice of man is not rooted in the moral character of man, but rather in his free and independent will. This means that there is no moral development in man, and good and evil are located in the actions of man and do not stem from man's nature. Sin is only in the separate acts of the will. He taught that man did not have a sinful nature, meaning that man is not predisposed or inclined towards sin. Sin or obedience is always the deliberate choice of the will, which is perfectly free. Adam was not created in a state of moral righteousness, but of moral equilibrium. Adam had moral neutrality and was created neither good nor bad (Berkhof, Page 234).

The Effects of the Fall

Adam chose to sin and thus he became sinful. To Pelagius, the idea of passing on sin in procreation is "absurd" (Berkhof, Page 234). Adam was no representative of mankind and so he did not pass on a sin nature or his guilt. His sin against God was an isolated event that had no consequences for anyone but himself. He did not see the human race as an organic unity under Adam. If there were such a thing as a sinful nature, it could be passed on from father to son, but sinful acts could never be passed down. Adam's sin was in no way passed down to his predecessors. He held that the doctrine of transmitted sin and original sin was blasphemous and it would make God unrighteous to do such a thing. Original sin changes the nature of man from good to bad and that would make God the author of evil. He held that if man's nature were evil, it would be beyond redemption and Christ himself would have had to posses it. If Christ possessed a sinful nature he could not redeem himself much less man (Sproul, Page 38).

He held that all children are born in a state of neutrality, just as Adam was prior to his fall. He held that the only difference between man now and Adam when he was first created is that man has been given many bad examples to live by. The future of the individual is determined by his free choices (Sproul, Page 39). Pelagius did admit to the universality of sin and explained that it resulted from the imitation and habit of sinning that is formed by the exercise of the free will for evil and not by propagation (Calvin, 2.1.5). Pelagius held the view that because man is inherently free in his will and therefore possesses the ability to chose to do good at any moment in time, that man has the ability and the capacity of self determination to live a life of sinless perfection without grace (Pelikan, Page 313). He held that the will is neutral and it is effected, not by the sin of Adam, but only by its own exercise. If a will sins and forms the "habit" of sinning, then it continues to sin. Likewise, if the will is in the "habit" of obedience, then it continues to obey God. He claimed that man is a creature of habit (James, Lecture 12).

To Pelagius, grace was given to man to "facilitate" goodness and to make our pursuit of perfection a little easier. The grace given is not necessary to achieve sinless perfection, for man can be good apart from God's grace. He believed that some of the Jews and heathens have obtained sinless perfection. This grace is given to man in the law of God to instruct in right living. But grace is given not only through the law, but in the example of Christ. God's grace adds nothing to human nature, but is given as merit for good behavior to aid man to obedience (Sproul, Pages 40-41).


Thomas Aquinas was born in Roccasecca in southern Italy near Naples in 1224 or 1225. He was born to Landulfo and Teodora Carracciolo. He attended the University of Naples where he became involved with the Dominicans. In 1245, he began to study under Albert the Great in Paris, who was appointed to start a Dominican House of studies in Cologne. He took Thomas with him as a student and after four years earned a baccalaureate and was then recommended to be sent back to Paris to teach theology. There he was called upon to defend the new religious order and to teach at the university. He and a friend, Bonaventure, became the spokesman for the Dominicans and the Franciscans respectively, to defend against the charges brought against them. After three years in Paris, he returned to Italy for nine years. One day toward the end of his life as he was saying mass, a great change came over him, which caused him to cease writing. After being encouraged to complete his Summa Theologica, he said, "I can do no more; such things have been revealed to me that all I have written seems as straw, and I now await the end of my life." Early the next year he was called to attend a general Council of Lyon in 1274 when he became ill and shortly after died (Hutchins, Pages v-vi).

Man Before the Fall

When God created man, his body was in complete subjection to the soul and there were no inclinations for rebellion. Neither death nor illness had any hold on man. Man's power of reason was all in harmony with God, which resulted in man having peace of mind. This state of man is called "Original Justice," when man was subject to God and all creatures on earth were subject to man. The state of man was dependent on his submission to God. He was permitted to eat of any tree except for the Tree of the Knowledge of Good and Evil. Being seduced by Satan, the woman ate the fruit and gave it to Adam (Aquinas, Light of Faith, Page 217-220)

The Effects of the Fall

The sin of Adam changed the original state of man. For man's will was harmonious to God in full subjection, but after the fall, man had an appetite to no longer follow the established order.

Aquinas taught that the sin of Adam was transmitted to his progeny. He wrote in his Summa Theologica, "…we are bound to hold that the first sin of the first man is transmitted to his descendants, by way of origin" (Aquinas, Page 163). He explained this by expressing the solidarity of the human race. He believed that the whole human race is born of Adam and is to be considered as one man, since all have been given the same nature from Adam and Eve. Aquinas illustrated this unity by saying that all the members of a community are of one body, and the whole community is one man. The sin committed by one member is a reflection, not of the part but of the whole. The "disorder" in the man born of Adam is animated by the will of Adam and not of his own will. Because Adam generated his nature and moves all that originate from him. This sin transmitted to all of Adam's descendants is called original sin. He goes on to say that the actual sin committed by a member of the community is not the sin of the member, except as far as he is part of the man in Adam. Original sin is not the sin committed by a person, but is the reception of this fallen nature from Adam, which is why it is called a sinful nature (Aquinas, Pages163-164).

Aquinas taught that actual sin or "other sins" from Adam and Eve or of anyone else (i.e. parents) are not transmitted to their descendants. He gives the example that a "grammarian does not transmit to his son the knowledge of grammar that he has acquired by his own studies," rather the part of man that pertains to his nature is passed down to the next generation (Aquinas, Page 165). Therefore, all men have descended from Adam and have been born with original sin with the exception of Jesus Christ. If all did not receive this original sin, then all would not need redemption from Jesus Christ. But since original sin is transmitted to all of Adam's posterity through seminal generation, he further claims that original sin could be eliminated if the seminal generation were eliminated. He also held that original sin was passed down the generations through the father and not the mother. He claims if Eve ate of the fruit and not Adam, that original sin would not be passed down, but if Adam ate and Eve did not, then their descendants would have original sin (Aquinas, Page 167).

The will of man has been affected by original sin and is turned away from God, resulting in all other faculties being turned away from God. Also, Aquinas claimed that original sin is concupiscence materially, but privation of original justice formally" (Aquinas, Page 170).

Original sin consists of two elements. First is the loss entirely of original justice, and the second is the transmission of the sin of Adam that caused man's nature to be corrupt. As a result of this loss of original justice and the transmission of the sin of Adam, it stands that original sin is not given to one more than another. Original sin is equal in all men. Original sin is subject to the soul and not the flesh because the soul is the subject of guilt, while the flesh is not. The flesh has the character of punishment, while everything that accumulates to the soul from original sin is characterized by guilt (Aquinas, Page 170).

Original sin is inherent in a person and is therefore subject of the soul. Original sin further impacts the will and the inclinations of a person to commit sin. The effect of original sin is that it takes away completely the gift of original justice and it has corrupted the good of human nature—the natural predisposition to morality or goodness. This nature that is inclined toward virtue is connected to the fact that man is rational, and that man's rationality cannot be taken away completely even by sin or else man would not be able to sin. Therefore, Aquinas concludes that the good of nature cannot be lost entirely (Aquinas, Page 179). Original sin results in death and all other defects in human nature. God commands the results of a defective human nature to be punishment for the sin imputed. The punishment is threefold. First, man is subject to his own conscience; secondly, man is subject to others either in a temporal or spiritual sense; and third, man is subject to God. So, infringement of sin will result in punishment in all these ways.

Comparison of Views

As already seen in the preceding sections that the doctrine of original sin is an important doctrine because it carries with it the anthropological as well as the soteriological issues of the role of Christ and redemption. The theologians discussed have some differences as well as some similarities in their views of original sin. Now that the views of Augustine, Pelagius, and Aquinas have been discussed, it is the writer's intention to discuss the differences.

A striking difference with these theologians' views is that Pelagius saw Adam's sin as an isolated event independent of the rest of the human race. The only effect it had was that it was a bad example for the rest of humanity. To Pelagius, Adam was not a representative of mankind. On the contrary, both Aquinas and Augustine saw Adam's rebellion against God as greatly affecting the rest of humanity, because Adam was a representative of the human race. Augustine saw that the whole human race was involved in the fall of Adam and all that were "in Adam" were punished with him. He held the view that all men were united to Adam both spiritually and physically. He also held said that infants were not free from Adam's sin and that all men receive a sinful nature from being united to Adam in his fall. Aquinas saw all of humanity as born of Adam and is to be considered as one man.

Pelagius claimed that prior to the fall of man, man had a will that was neutral, neither inclined towards good nor evil. In fact, Pelagius claimed that the fall had no impact on his will, and that after the fall man's nature had not changed. He did not believe that man had original sin. Pelagius held that the human will was only affected by it own action. Man got in the "habit" of sin or obedience. He also claimed that children are now as Adam was prior to the fall. Contrary to this, Augustine and Aquinas held that the will was affected by Adam's sin. Augustine claimed that man was created "good," meaning that man has not a morally neutral will, but a will that is naturally inclined to obey God. Man, prior to the fall had the posse peccare and the posse non peccare, but after the fall man had the non posse non peccare. The sin of Adam was passed on to his descendants and so was his sinful nature. All of mankind was now inclined to do evil. Aquinas also held a belief contrary to Pelagius. He claimed that man's body prior to the fall, was in complete subjection to his soul and there was no inclination for rebellion. Man's reason was in harmony with God, but after the fall, man no longer had the desire to follow God's order. Adam's sin was transmitted to his progeny and changed the original state of man.

Pelagius also claimed that even if there was no fall and Adam lived obediently to God, he still would have died. Both Aquinas and Augustine disagreed with this and claimed that Adam would have lived forever if he had never sinned against God.


The great doctrine of original sin has been an issue of debate in the past. One's view of original sin determines how one sees the particular role of grace in redemption. If original sin has had little impact, then the work of grace is small, but if one's view is that original sin has greatly turned our minds and hearts away from God, then grace plays a much greater role in redemption.

Augustine's, Pelagius', and Aquinas' views on original sin have been discussed. Their efforts in study have helped pave the road to modern orthodoxy. The views of each theologian in regards to man's condition, both prior to the fall and after the fall, have been expressed. We saw that Augustine taught that all of humanity would spring out of Adam. The fall of Adam negatively affected humanity in that man can only sin. Pelagius' view was that humanity was not organically connected to Adam, and his sin was of no consequence to anyone but himself. Man was created morally neutral and his free will was not impacted as a result of the fall. Aquinas believed that before the fall Adam was not inclined to rebel against God, but after the fall Adam's descendants were born with original sin as demonstrated by the sinfulness of all mankind.


Aquinas, Thomas. Light of Faith: The Compendium of Theology. New York: Sophia Institute Press, 1993.

________. Summa Theologica. Volume I and II. Encyclopedia Britannica, Inc. Chicago, Illinois, 1987.

Augustine. The City of God. New York, New York: Penguin Books, 1972.

________. Confessions. New York, New York: Penguin Books, 1961.

________. On Christian Doctrine. Encyclopedia Britannica, Inc. Editor, Hutchins. Book 18. Chicago, Illinois: The University of Chicago Press, 1978.

Berkhof, Louis. Systematic Theology. Grand Rapids, Michigan: Eerdmans Publishing Company, 1996.

Calvin, John. Institutes of the Christian Religion. Philadelphia, Pennsylvania: The Westminster Press, 1960.

Geisler, Norman L. What Augustine Says. Grand Rapids, Michigan: Baker Book House, 1982.

Pelikan, Jaroslav. The Emergence of the Catholic Tradition (100-600). Chicago, Illinois: The University of Chicago Press, 1971.

Sproul, R.C. Willing to Believe. Grand Rapids, Michigan: Baker Books, 1997.

Warfield, Benjamin Breckinridge. Calvin and Augustine. Philadelphia, Pennsylvania: The Presbyterian and Reformed Publishing Company, 1971.

This article is provided as a ministry of Third Millennium Ministries (Thirdmill). If you have a question about this article, please email our Theological Editor.

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