As with St. Paul’s anthropological doctrine, we will not present an exhaustive analysis of doctrinal development but will only provide citations and commentary that we believe adequate to demonstrate that the tripartite view of man, which we have proposed, is neither novel nor unorthodox, even though it departs somewhat from the preferred formulations of contemporary (post-Aquinas) theologians.
Very early in the history of the Church we encounter the body-soul-spirit formulation via St. Irenaeus. Before we offer any citations, we will point out that Irenaeus was combating the errors of the Gnostics who had taken what would have been a normal ‘tripartite’ anthropology and absolutized each part as if it were its own class of human beings. These classes were the hylics, the psychics, and the pneumatics, each category corresponding to a tendency either ascending, neutral, or descending, with the result being that salvation was reserved for the third type only and determined by the nature bestowed on the individual and that alone.
In opposition to this extreme systematization, Irenaeus writes:
“The soul and the spirit are parts of man, they are not man himself; for the perfect man consists in the commingling and the union of the soul receiving the spirit of the Father and the admixture of that fleshly nature which was molded after the image of God.”
As if in anticipation of the confusion displayed by contemporary theologians at this (quite Biblical) distinction between soul and spirit, who may wonder if this ‘spirit’ is a created and individuated thing or if it is the very Holy Spirit Himself, Irenaeus clarifies:
“For if any one take away the substance of flesh, that is, of the handiwork of God, and understand that which is purely spiritual, such then would not be a spiritual man but would be the spirit of a man, or the Spirit of God…But if the Spirit be wanting to the soul, he who is such is indeed of an animal nature and…carnal.”
In short, the fully realized man is possessed of three ‘parts’, although the spirit may, in actuality, be lacking, in which case the being in question is called ‘carnal’. This is remarkably similar in form to the doctrine of St. Paul, speaking frequently of the ‘spiritual man’, and so on.
If there were any doubt about the necessity of considering the ‘spirit’ as a part of normal spiritual anthropology, Irenaeus continues:
“For that flesh which has been molded is not a perfect man in itself, but the body of a man, and part of a man. Neither is the soul itself, considered apart by itself, the man; but it is the soul of a man, and part of a man. Neither is the spirit a man, for it is called the spirit, and not a man; but the commingling and union of all these constitutes the perfect man.”
And finally, with utmost clarity:
“[T]here are three things out of which, as I have shown, the complete man is composed—flesh, soul, and spirit. One of these does indeed preserve and fashion—this is the spirit; while as to another it is united and formed—that is the flesh; then that which is between these two—that is the soul, which sometimes indeed, when it follows the spirit, is raised up by it, but sometimes it sympathizes with the flesh, and falls into carnal lusts.”
It is interesting to observe the dismay of certain moderns at this exposition. Taking as their starting point a simple body-soul dualism, the arguments of Irenaeus must be very confusing indeed. What we find, then, is that they immediately begin accusing the saint of having confused his anthropology, or else they engage in all manner of mental gymnastics in order to show that he does not actually say what he obviously says. We think he speaks clearly enough for himself.
Next, we come to Clement of Alexandria, a younger contemporary of Irenaeus. In the text that follows, Clement is commenting on the Gospel of Matthew 18:20, which reads:
“For there where two or three are reunited in my Name, I am in the midst of them.”
Regarding this passage, Clement passes through the levels of meaning, beginning with the most literal and exterior and eventually touching on the most profound, saying:
“In another sense the three are passion (thymos), desire and reason, the flesh, the soul and the spirit according to another denomination…When, having surpassed thymos and desire, man will love in deed the creation of God and the Creator of everything, he will live as gnostic…already ‘one’ here below in his judgement and truly spiritual, inaccessible in everything and everywhere to the reasonings of passion and desire, completed in the image of the Lord by the Craftsman himself, a perfect man, worthy of being called brother by the Lord, and friend and son at the same time. In this way the two and the three are reunited in the gnostic man.”
Somewhat later, during the 4th century AD, we are given the teachings of St. Gregory of Nyssa. Although complex, the anthropology of St. Gregory is summarized as follows:
“What constitutes the image of God, and therefore what belongs to man by nature, is the faculty of pure knowledge, discrimination and supreme illumination, in other words the intellect [nous]; the rest, the desiring soul and the affective soul, is added.”
Also in the 4th century, a text from St. Epiphanius, which is short but significant because nested within a creed, a creed which in turn served as a kind of preliminary draft of the Creed of Constantinople. It runs as follows:
“We believe…in Jesus Christ, the Son of God…who was made man, that is, has taken on a perfect human nature, soul, body, and spirit and all that is of man, except for sin.”
It is notable that this text was given as a kind of correction to the “trichotomism” of Apollinaris and is powerful because it sought to correct the heresy of the latter without, for all that, oversimplifying the matter.
Now again in the 5th century, the giant figure of St. Augustine appears, and he writes:
“There are three things of which man consists—namely, spirit, soul, and body [spiritus, anima, corpus]—which again are spoken of as two, because frequently the soul is named along with the spirit; for a certain rational portion of the same, of which beasts are devoid, is called spirit: the principal part in us is the spirit; next, the life whereby we are united with the body is called the soul; finally, the body itself, as it is visible, is the last part in us.”
Could we hope for a more lucid agreement with everything we have said up to this point?
 Adversus haereses, Book V, 6, n. 1.
 Ibid., Book V, 9.
 On the Soul and the Resurrection.
 Dumeige, La Foi catholique, noum. 5.
 De fide et symbol, X, 23.