In many contemporary debates concerning the priesthood, one rarely hears a genuinely theological account of what makes a priest a priest. This defect rests, at least in part, upon a failure to consider the metaphysical nature of the Catholic priesthood, as it can be defined from rational reflection on the data of revelation. Instead, one generally finds a parading of the supposed results of historical, biblical, psychological, or sociological “research,” most of which is pressed into the service of revolutionary proposals at odds with orthodox Christian tradition and dogma. Yet if we are to make any sense out of our doctrine and practice, the theological-metaphysical account cannot be left aside. We have to go back to the basic truths that occupied the minds and hearts of the great theologians of the past, focusing our attention on the permanent and perennial, the fundamentals of what our faith teaches us about our Lord.
This article will give the outlines of an approach which might be called incarnate realism—that is, a consideration of the link between the truth that Jesus Christ, as true God and true man, is the one Mediator between God and man, the Eternal High Priest after whom all priests must be modeled, and the truth that the Word became flesh not by assuming human nature in the abstract, but by assuming a concrete or individualized human nature—namely, as male, as a member of one of the sexes. By holding these two elements together, one can clarify the intrinsic rationale of our traditional teaching, making it easier in turn to assess the relative worth of other theories or of specialized research.
Priesthood in itself and by participation
St. Thomas teaches that any creature is a being (ens) by participation and not by essence, because it receives its act of being (esse) from, and thus wholly depends upon, the God who is his own being (ipsum esse per se subsistens), who is wholly “in act,” of whom the participant is a likeness or imitation. If one takes this term ‘participation’ in its precise metaphysical meaning, it is clear, by extension, that Jesus Christ is the one High Priest in whom all other priests participate: their priesthood is purely a gift of sharing in that priesthood which Christ possesses in Himself and not through another. This fundamental truth does not deny that each priest is truly a priest; it simply denies that he can be considered such “in or of himself” (a se), just as all creatures are truly beings and causes, but none is the First Cause who is self-subsistent being, none can exist or bring about effects save by the indwelling presence and causality of that First working intimately within them, sustaining them at every moment. The ministerial priest is a true minister precisely as participating in the priesthood of Christ. His priesthood not only makes them to be His ministers, it is the only reality by which they continue to be and to function as “other Christs.” As with any exemplar cause, the priesthood of Christ is the origin or principle as well as the goal or finality, the terminus a quo from which the form is taken and the terminus ad quem to which its activity tends. And as we name any motion both from its source and its end, so too the priest is called sacerdos because his state is at once derived from and oriented to Christ, the summus sacerdos foreshadowed by Melchisadek, of whom the Roman Canon solemnly reminds us after the miracle of transubstantiation effected by the priest. The failure to recognize this relation of exemplarity between Christ and His minister engenders many serious errors in the theology of priesthood.
Since the fundamental role of a priest is to mediate between God and man, it follows that Jesus Christ, in whom the divine and human natures are united in the very Person or hypostasis of the Word, is the ontological Priest from the moment of His conception in the womb of the Virgin Mary, which, as the Fathers taught, was the temple of His priestly consecration. As St. Cyril of Alexandria teaches: “the Word of God . . . when He became flesh and man like us, became High Priest and our Apostle.” St. Thomas clarifies: “Although Christ was not priest as God but as man, yet one and the same [Person] was priest and God.” He not only mediates, He is the mediation between God and man, and that is why only His grace can justify, can sanctify, the soul. All other priests are ministerial, that is, ingrafted through ordination into this eternal priesthood of Christ. They are ordained in order to channel His priestly blessings and graces to the people; they are not made into “other priests,” independent sources of sanctifying grace, as though one could number them alongside of Christ—“Jesus, the first priest of the New Covenant; St. Peter, the second; St. John, the third,” and so on—just as it is impossible to number God alongside His creatures as though He were one thing among many. Their dignity, their office, the origin and guarantor of their priestly being, is to conform to Christ, to offer the holy sacrifice in persona eius. They cannot therefore claim any separate dignity, as though the office “belonged” to them. It belongs, personaliter et essentialiter, to Christ alone. He is the one mediator between God and man; when priests act in His name, or more accurately, act mysteriously in His place (and that is essentially what it is to be a priest: to be and to act as Christ in many different places and times), they are not so many additional mediators; they are effaced, assimilated to Christ, their leader and archetype, and lose their personal distinctiveness. Individual priests differ as individuals, not as priests. Their distinctiveness is a function of their personality: in them there can be and certainly are varying levels of intellectual power, moral strength, artistic creativity. Indeed, there are degrees of priesthood in terms of authority of rulership. There cannot, however, be degrees in the very power of confecting the Eucharist, a power corresponding to the sacramental character of Holy Orders. Either a man can act specifically and totally as Christ in offering the holy sacrifice, or he cannot. There are not many priesthoods of the New Covenant; there is but one, Jesus Christ’s. Its powers, gifts, and activities flow through the many hands and mouths of His ordained servants, who are images, icons, “personal sacraments” of the one High Priest.
Saying Mass in persona Christi
It is Jesus who, mystically dwelling in His earthly minister, offers perfect worship to the Blessed Trinity during Holy Mass, and this perfect worship, this act of total surrender in love and obedience, is the immolation of Christ Himself, Priest and Victim, upon the altar of the Cross. During Mass, especially when the Canon shifts to the words of institution, the priest is Christ in a true but ineffable way; he does not speak in his own name or act from his personal powers, which are infinitely incommensurate with the divine action and passion taking place in the sacred liturgy. Rather, he stands as Christ, for Christ, and works through Him, with Him, and in Him, so that he ceases, as it were, to be Fr. So-and-so, but is conformed to the High Priest offering the one supreme and all-sufficient Sacrifice of the Cross. This is the heart of the mystery of the priesthood, and it explains two things: first, why Protestants are wrong to accuse Catholics of setting up “many mediators” between God and man, undermining the Savior’s uniqueness; and secondly, why a woman could never be a priest.
Before returning to the latter point, a brief discursus is called for. Bearing in mind what has been said to this point, one may see another reason why the priest offering the holy sacrifice should face ad orientem (towards the east, in the direction of the altar)—an “orientation” which fundamentally symbolizes the unified longing of the People of God as it goes on pilgrimage, awaiting the Second Coming of the Lord. When he faces ad orientem, the priest is no longer in a closed circle of earthly dialogue with the congregation; he is subsumed into the archetype of Christ, he merges silently into his office, his personality yields to the one overriding concern of the liturgy, namely, that the sacrifice of Calvary be renewed for our salvation by the invisible Lord working through His visible ministers. In this way each Mass not only commemorates the first advent of Christ in poverty, but foreshadows His final advent in glory. The historically contingent celebrant is hidden and momentarily forgotten in the liturgical action, so that Jesus Christ may be all in all, Alpha and Omega. At the most solemn moment in the Mass, the celebrant should be positioned in such a way that his voice and his body and everything about him is totally assimilated to Christ, the High Priest. Whether intended or not, the liturgical “reforms” had the most unfortunate practical effect of making it often seem as though the priest, in his strictly personal or individual aspects, is the one “doing” or enacting the divine mysteries, when nothing could be further from the truth. If an icon draws attention to itself as a piece of painted wood, it ceases at that moment to function iconically and slips into the category of mere artifact. Similarly, if a priest as “this man” becomes the object of attention, he ceases at that moment to represent mystically the High Priest on the altar of the Cross and slips into the category of minister in the Protestant sense, one who “facilitates the ceremony.”
The same thoughts show, at least in part, the rich symbolic meaning of the sanctuary layout as it evolved in Western Christianity—why, namely, the altar is architecturally united with a tabernacle which acts as the base of a prominent crucifix. The Real Presence of Jesus in our midst follows from His gift of Himself in the Holy Eucharist, which in turn was given as a living memorial of the Passion, Resurrection, and Ascension, as the Roman Canon recalls immediately after the consecration. The Eucharist is the very Body of Christ broken upon the altar of Calvary and glorified on Easter morning. The sacrament of supreme love, through which man is united to God in the most intimate of all friendships, is identical with the sacrifice of supreme love by which sinners, enemies of God, are reconciled to Him in the Blood of the Lamb. The crucifix to which all eyes are drawn represents the very act which unites altar and tabernacle, the death which gives life and the life which conquers death, reconciling the sinner and nourishing the saint. “And I, when I am lifted up from the earth, will draw all men to myself” (Jn. 12:32). The integration, in an ascending visual order, of the altar of oblation, the tabernacle of presence, and the crucifix of the Lamb mystically expresses the profound inner connection between suffering, love, and glorification. Each architectural element reinforces the other, voicelessly speaking the entire drama of salvation. The profusion of visual symbols, the overlapping layers of meaning, far from introducing confusion, are on the contrary just what makes it possible for us, tied as we are to our bodily senses and ways of knowing, to come slowly and by small steps into the presence of Jesus, to begin to taste and see the infinite mystery of the Lord who is beyond all symbols and cannot be comprehended by reason alone.
The scandal of particularity
The theological vision of priesthood traced out here lends powerful support to the dogma that the male sex is the only valid subject or recipient of Holy Orders—with the necessary corollary that women cannot be made priests. As we have seen, since ordination does not make a “new” priest but rather extends into a new individual the hypostatic activity of Christ’s incarnate priesthood, the ordained individual himself must conform to the exact nature of Christ’s humanity, in and through which Christ is a priest interceding with God for mankind; the ordained minister in his own person must not be anything which conflicts with the iconic reality of the human nature of Jesus. Christ took on human nature as a man, as a male, by His eternal decree and choice. Only by divorcing “the Jesus of history” from “the Christ of faith,” as many modern exegetes have done, can one maintain that the ministerial priesthood is not a trans-temporal icon of the God-Man, the sole Mediator. Because Jesus Christ is one reality, not two—not a contingent historical figure and then, over and above that, the archetypal Messiah or Savior—everything essential to His humanity is part of His factual identity, part of the inmost being of the Incarnate Word. The Incarnation is the supreme “scandal of the particular”: the Son of God becomes man (scandal enough for the abstruse metaphysical mind!), Christ the Son of Mary, Christ the male. His humanity, His human filiation, His sex, all pertain absolutely to who He is; if one of these is bracketed off, the others are implicitly negated. “O the depth of the riches and wisdom and knowledge of God” (Rm. 11:33): how dare we question the infinite mystery of Christ’s particularity! The Son of God did not come to us as a sexless universal, an androgynous humanoid. He came as the Bridegroom. The human nature of Christ is the exemplar for all human beings and the means whereby we can imitate Him; but Christ as man, as a male, is the exemplar for all individual men called to minister in his place as priests, as sharers of His one eternal priesthood and ministers to His beloved Bride.
This is no mere matter of symbolism in the conventional sense, although that is important enough, as anyone who appreciates the nature of religious rituals can see. Nor is it merely a matter of Christ’s example, since example is always based upon a prior principle, a commitment to some truth according to which one sets an example. Our Lord did not just “do things” for no good reason, He did everything with infinite wisdom and discernment, and God forbid we should say that He feared human custom or merely wanted to go along with the cultural practices of His time—He who broke conventions, who broke what the Jews took to be binding laws, whenever they impeded the accomplishment of His saving work. Nor, finally, could it be a matter of ancient apostolic custom, or even of unbroken ecclesial custom, since custom is only valuable to the extent that it, too, is founded upon a truth that cannot be gainsaid. This truth is the facticity, the scandalous and never-to-be forgotten facticity, of the Son of God incarnate in this individual human nature, at this time, in this place, with this way of life, with these words and signs and teachings, taking flesh as a man from the maiden Mary. The eternal deity, King of kings and Lord of lords, the very infinitude of absolute perfection and holiness, as in a flash, takes on flesh—irrevocably takes on flesh in this way and only in this one way.
The Catholic faith from its infancy has had to fight continually against the cheapening of this mystery. It fought against those who, holding that Christ was only divine, made of His humanity an illusion played upon our carnal senses; it fought against those who wanted Christ only to be human, a great prophet, a great moral teacher; and to this day it fights against the still more subtle heresy which, while seeming to admit that Christ is true God and true man, slides away from the silent worship of this overwhelming mystery and shifts all attention to ethics or social justice, as though the truth of the Incarnation could be acknowledged with a pious bow and then for all intents and purposes forgotten in the day-to-day life of the Christian community. The Church fights against all these things, for they are all varieties of the ever-recurring disease of reductionism, which would have revelation on the cheap, tailored to our own ideas, our proprieties, our preferences, our sense of reasonableness and fairness. But God alone is truth, He alone is holy, and if we or our theology are to have any truth, we must conform totally to the revelation He made, humbly embracing the word of God exactly as the Church has received it from her Founder.
The heresy of contemptum carnis
Because Jesus is the Eternal High Priest, sole Mediator and source of grace, it follows that Christian men who receive the privilege of acting at the altar in persona Christi are acting exclusively as His “separate and animated instruments”—free and intelligent, but nonetheless instrumental, conduits of the priestly power which is His by nature and by right. The Incarnate Word is a priest per se et in se, while the ordained are priests per ipsum et cum ipso et in ipso, as participating in the historical and eternal reality of Christ’s ontological priesthood. Consequently, they must not be other than Christ in His human identity. They can be drawn from every nation, race, and tongue, but they cannot be female, since sex is not accidental to the constitution of the human being in the way in which skin color or height or weight or age or language is accidental. The only way to oppose this conclusion is to adopt a rigorously dualistic position according to which sex or sexuality (maleness and femaleness) is not really part of human nature, not on the “inside” of its being, but instead some kind of supervening accident separable from and independent of human nature as such.
At this point, a potential difficulty must be cleared up. In metaphysical strictness, the human soul cannot be male or female in itself, since it is a subsistent spiritual entity, and intellect as such is non-sexual. Sexuality is a property of animate body; only a living physical organism can be actually male or female. However, the soul alone does not constitute human nature; a human being is a rational animal composed of soul and body, the one as form, the other as matter which receives being through form. The individual or concrete human being is man or woman, and the separated soul after death remains part of an incomplete nature until, at the resurrection of the dead, it is reunited with its body in order for it to function again as the formal principle of an integral physical nature. As long as the human soul is considered abstractly and as a subsistent entity, it is non-sexed; but considering the soul abstracted from the body means that we are no longer speaking of a complete human nature, but only of a detached and naturally incapacitated intellect—one which, moreover, is not fully what it was, since its history, its very life, was bodily, and all of its activities were founded in or assisted by the body. In other words, just as the soul never existed bodilessly, human nature in its fullness does not exist bodilessly either. As St. Thomas teaches, the soul is essentially unibile—unitable to body and desirous of uniting to body, needing this union for its full ontological perfection.
The dualist, on the other hand, denies any intrinsic connection between sexuality and the human soul, which is taken to be purely spiritual. Indeed, a consistent dualist has to maintain that sexuality is not only an extrinsic accidental feature but an imperfection, a lessening of human dignity, something to be overcome, thrown off, superseded; the condition of sexuality is a fall for the soul, an imprisonment in matter (which is equated with, or viewed as the byproduct of, evil). In heaven everyone will be a perfect hermaphrodite, or rather, a neutered human being without any sexual characteristics. But is it possible for someone who holds any version of this position to be in any meaningful way a follower of that revelation which at its beginning solemnly declares: “Male and female he created them,” and towards the end, that husband and wife are a living image of the eternal nuptial bond between Christ the Bridegroom and the Church, His Bride? There are many “closet dualists” who would not overtly reject Scripture but who, perhaps ignorantly all the while, espouse positions that either presuppose or lead to anti-incarnational (anti-physical, anti-bodily, anti-sexual) heresy. One begins to discern the subterranean connections between a seemingly theoretical heresy and the rampant sexual perversions of our day. These perversions are not rooted in an exaggerated opinion of the goodness of the flesh created by God. They are rooted precisely in a hatred of the flesh as an enemy to be conquered and subdued by detached calculation, in a rejection of the manifest purposefulness of sexuality which accounts for the polarity and harmony of the sexes, in a denial of the sacredness of the living body as the temple of the human soul and of the divine Spirit.
Since there is only one ontological Priest, Jesus Christ, ordained men are called priests per posterius (by extension or subordinate predication) owing to their sacramental connection to Him. A special bond to the full theandric reality of Christ is bestowed on them—hence the de fide doctrine that ordination confers an ineradicable sacramental character distinguishing the priest from all other believers, just as baptism confers a character distinguishing the baptized from the unbaptized—and this bond between High Priest and minister includes the mission, the imperative, to imitate Christ as Priest. As Christ is Priest in the totality of His incarnate reality, it follows that the one to be ordained must be male, since otherwise an intrinsic element of the ontological basis of conformity to the High Priest would be lacking.
“Woman, behold your son”
A reverse analogy to the priesthood may be found in the maternity of the Virgin Mary, who, whether nursing the newborn Christ-child or holding the crucified Savior in her arms, offers to our gaze the other pole of incarnate realism. The Virgin Mary in her femininity, in her womanhood, is the Mother of Christ and the Mother of God; in her historical individuality as the woman of faith, the first to believe, the one whose fiat caused the beginning of the redemption in time, she is the Mother of all beloved disciples and the Mother of the Church. Her vocation as the God-bearer, her role in salvation history, is unique and unrepeatable, the most perfect created mirroring of the priesthood of her male Son. The Word became flesh in her womb; the Incarnation of the Son and the Motherhood of Mary are correlative scandals of the particular. Considered in her metaphysical identity as a woman, Mary’s femininity, and a fortiori her maternity, cannot be shared in by men, nor can the priesthood of Christ, insofar as He is male, be shared in by women, who cannot be conformed to Him in this essential respect. All women have a special relation to Mary, namely, their common sexual identity, and their virginity or their maternity; all men have a special relation to Christ the man, which makes them potential candidates for the priesthood. Just as it would be absurd for a man to complain that he can never be ontologically related to Mary in her womanhood and her motherhood, so too it would be absurd for a woman to complain that she cannot be assimilated to Christ as regards His sex.
One might object that this comparison illegitimately mixes together the natural and supernatural realms, for while there is only one Mary and only one Christ, there are many ordained priests who mystically carry on His work, but no mothers who essentially continue hers. It should be granted, first of all, that the analogy is imperfect; it does not hold in every respect. There is an irreducible difference between the ordained priesthood which participates in the mediation of Jesus Christ, and the sexual likeness all women share with the Mother of God. All human beings are called to benefit from and participate in the redemptive work of Christ, and all Christians are called to imitate, venerate, and turn lovingly to the Virgin Mary. In this respect “there is neither male nor female,” since the redemption of Christ is for all without distinction, and Mary’s unconditional obedience and perfect trust stand as the everlasting model of the response all human beings should make to God. But we are concerning with the special link that women have to Mary, and the special link that men have to Christ. The essential point to consider is the supernatural dimension of the Virgin’s maternity, which elevates the female sex to its greatest dignity and gives it a privileged ontological symbolism that the male sex cannot share. Mary’s maternity is a supernatural mystery encompassing her entire being, even as the Son of God assumes and encompasses human nature in its totality. It is arbitrary to say that Mary’s sex matters less than or more than Christ’s; that is to miss the point of salvation history. In the Providence of God, Mary’s sex no less than Christ’s is absolutely meaningful and bears consequences for all men and women from the dawn of creation to the end of time. It is in virtue of the Mother of God that woman or the feminine exemplifies the Church, the Bride of Christ, the believing soul; it is in virtue of Jesus her son that men exemplify Christ, the Bridegroom of the Church, the High Priest. Both men and women belong to the Church and receive through her the grace of Christ, who is head of the mystical body; but this mutual belonging no more introduces sexual confusion than the fact that husband and wife are equally spouses and equally participate in the same grace of matrimony—for indeed they still have, and could not not have, their distinctive roles in the family as regards procreation, the rearing of children, and the regulation of the household. Equality of nature is not incompatible with distinction of office.
[Originally published in Homiletic & Pastoral Review 100.7 (April 2000): 21–29.]
 The eclipse of traditional metaphysics in the modern age contributes in no small measure to the confusions rampant in debates on theological questions. While Plato and Aristotle were not inspired authors, their distinctions and discussions penetrate to the core of natural reality and furnish the Christian theologian like St. Bonaventure or St. Thomas Aquinas with the tools for exploring the foundations and the meaning of revealed truths. As soon as the metaphysics of participation is ignored, the doctrine of the priesthood, for example, falls into incoherence.
 Special attention should be given to two other essays which are closely connected with mine: John Saward, “The Priest as Icon of Christ,” in The Priest, vol. 50, n. 11 (November 1994), 37–48; and Josef Pieper, “What Makes a Priest?” in J. Pieper, In Search of the Sacred (San Francisco: Ignatius Press, 1988), 51–81. These essays follow the same method of ‘incarnate realism.’
 St. Thomas, Summa theologiae (ST) IIIa qu. 4, aa. 4 and 5; qu. 5, aa. 1 and 2. See qu. 18, a. 2: “The Son of God assumed human nature together with everything pertaining to the perfection of human nature. Now in human nature is included animal nature, as the genus in its species. Hence the Son of God must have assumed together with the human nature whatever belongs to animal nature.”
 ST Ia qu. 3, a. 4; qu. 4, aa. 2-3; qu. 6, a. 3.
 ST Ia qu. 8, a. 1; qu. 104, a. 1; qu. 105, a. 5.
 ST IIIa qu. 22.
 Third Letter to Nestorius (DS 261).
 ST IIIa qu. 22, a. 3, ad 1.
 ST IIIa qq. 8 and 26; also, qu. 19, a. 4.
 See, e.g., ST Ia qu. 30, a. 3.
 This statement does not intend to deny that all of the baptized participate in the priesthood of Christ, nor that bishops receive the gifts and powers of the priestly office in a fuller way than priests. However, it must be borne in mind that the common priesthood of the laity is nothing other than receiving from the Lord the power and privilege to offer oneself and the world to God as a free and acceptable oblation, as a sacrifice of faith and love. It does not include the special power to reenact the Holy Sacrifice of Calvary, the one all-sufficient oblation through which all other offerings acquire eternal value. Nor does the increasing concentration of powers in deacon, priest, and bishop suffice to constitute three “grades” of priesthood. Strictly in terms of the power to offer the sacrifice at the altar, priest and bishop are equal; from the same point of view the deacon is radically unequal to either one.
 See Saward, “Priest as Icon.”
 See Joseph Cardinal Ratzinger, Feast of Faith, trans. Graham Harrison (San Francisco: Ignatius Press, 1986), 139–145. Assuming a liturgy celebrated in Latin according to the norms of the Church (whether it be the Modern Roman Rite or the Classical), arguably the only time the priest should turn his face to the people for an extended period is when he is doing the readings in the vernacular and preaching the homily. Undoubtedly, the homilist is supposed to be teaching on behalf of the Church, but the homily is “paraliturgical”; it is a recommended practice, but not an integral part of—not essentially related to—the unbloody renewal of the sacrifice of Calvary and the faithful’s participation in its fruits by receiving holy communion. It is fitting therefore that time when the priest addresses the people in the vernacular should be the time when he is least hidden within, least plunged into, the dramatic action of the altar.
 See Peter Kwasniewski, “Traditional Liturgy as a Liberation from Egoism,” Homiletic and Pastoral Review vol. 99, n. 4 (Jan. 1999), 19–28.
 ST IIIa qu. 25, a. 3.
 To attempt to “clarify” or “simplify” the Mass by removing interwoven layers of symbolism is nothing other than to distort the sacred mysteries which are too bright for human eyes, too strong for human ears. To put it somewhat provocatively, the Mass should be celebrated in such a way that no one can fully understand what is taking place; the very structure of the sanctuary, the very rite of the liturgy, should be fathomless, inexhaustible, in their symbolic meaning. The worshiper should be able to attend Mass every day of his life and never reach an end of new discovery and rediscovery. If everyone suddenly “understood” everything, they would no longer be understanding Christ, but some finite human construct. They would, in fact, be understanding themselves, their own small world, not the Lord and His infinite wisdom. It is for this reason that much of post-conciliar worship is little more than self-worship; we re-design churches and celebrate liturgies according to our own time-bound, earth-bound ideas, failing to remember that even the greatest mystics—or rather, especially the greatest mystics—bowed humbly before what they could not comprehend.
 It is not a question of “withholding” something from women; if the very thing is impossible, nothing is withheld, just as the fact that men can never carry a child inside of them is not properly speaking a deprivation, a cosmic injustice, even though on the natural plane there is no more perfect expression of incarnate love than the conception and growth of a child in its mother’s womb.
Dr. Peter Kwasniewski, Thomistic theologian, liturgical scholar, and choral composer, is a graduate of Thomas Aquinas College and The Catholic University of America. He has taught at the International Theological Institute in Austria, the Franciscan University of Steubenville’s Austria Program, and Wyoming Catholic College, which he helped establish in 2006. He writes regularly for Catholic blogs and has published seven books, the most recent being Tradition and Sanity (Angelico, 2018). For more information, visit www.peterkwasniewski.com.