When I was an undergraduate at an Evangelical university and beginning to think more deeply about gender, there were two basic paradigms on offer: egalitarianism and so-called complementarity. In those days—the early 2000’s—the pop-Christian livre de jour was a book called Wild at Heart: Discovering the Secret of a Man’s Soul by Jon Eldredge. This bestseller, ubiquitous in evangelical circles, provided a dizzying mash-up of fairy tale tropes, pop culture references, and bible verses, in order to unlock the hidden mysteries of the masculine heart.
The basic premise of Eldredge’s book is that God creates men to be chivalrous Beasts with a hunger for adventure, a need to fight battles and rescue a Beauty. And a woman’s telos, conversely, is to be that Beauty who is rescued and swept up in the man’s heroic adventure. Eldredge presents men and women as two partial reflections of God: “There is a masculine heart, and a feminine heart, which in their own ways reflect or portray to the world God’s heart.” These two “hearts” are not so much complements or analogues, but polarized opposites. A man’s heart is “wild and strong and valiant” hankering for exploration and conquest, while a woman simply longs to be pursued and rescued: “the world kills a woman’s heart when it tells her to be tough, efficient, and independent.”
This perspective was an emblem of gender complementarity in the Evangelical understanding. Finding little to relate to in this vision of woman as passive princess, I sought solace in egalitarianism—a form of Christian feminism preoccupied with establishing a biblical basis for the fluidity of gender roles and the spiritual authority of women. The framing mantra in this perspective—and central hermeneutical key—is a phrase gleaned from Galatians 3:28, “there is neither male nor female, but you are all one in Christ Jesus.” Here, prescriptive roles were thankfully dissolved, but so was meaningful sexual difference altogether. In both of these paradigms, dignity was in direct tension with difference. To affirm equal dignity, the egalitarian downplayed difference. Reckoning seriously with difference, on the other hand, detracted from woman’s dignity and full personhood, as in Wild at Heart.
These two basic perspectives—gender unity and gender polarity—can be traced back to the foundations of Western thought. Philosopher Prudence Allen, in her epic three-volume work The Concept of Woman tracks the evolution of “woman” as a philosophical concept from the pre-Socratic age to the present.
There is, quite simply, nothing like Allen’s magnus opus in the realm of philosophy or women’s studies. My own graduate program in women’s studies, for example, cast a backward glance only as far as the enlightenment, staying firmly entrenched in the theories of the twentieth and twenty-first centuries. But Allen goes back to the genesis of philosophy itself, meticulously cataloguing several basic theories of gender relations and how those theories have developed over the arc of Western intellectual history. Her work is not only descriptive, but evaluative; she examines the philosophical and theological implications of each approach, concluding that one theory stands out among the others as best able to uphold two key principles in a healthy, fruitful tension: first, the equal dignity of man and woman, and, secondly, significant differentiation between them.
The theory of “gender unity,” which I first encountered in the form of evangelical egalitarianism, can be found in nascent form in Plato. In his Republic, Plato describes the ideal city-state, one capable of realizing justice, with all the various parts working together harmoniously. Plato’s city is ruled by a class of philosopher-guardians who are suited by nature and training to wisely guide the lower classes of soldiers, merchants, craftsmen, and farmers. Notably, Plato admits women into this elite group. Because Plato’s philosophy, as a whole, downplays the material and elevates the rational, the generative roles that distinguish men from women carry less significance than their shared rationality. The body matters little when compared to the mind.
Still, one has to reckon with the messy, bodily transmission of human existence somehow, even in the most Platonic of utopias. So, Plato does his best to sever those pesky familial ties that bind one to spouse and offspring by eliminating marriage and shifting the “petty evils” of childrearing to a state-run “rearing pen”—not unlike Simone de Beauvoir’s socialist vision of collective childrearing in The Second Sex. Platonic equality between the sexes is ultimately expressed as sameness; women must shed, as much as possible, their female distinctiveness, in order to rule alongside men. Plato, then, affirms equal dignity (more or less), but not significant differentiation. This is the same basic impulse at work in egalitarian feminism—one that ultimately downplays the significance of the body altogether, particularly in its sexuate character.
Aristotle brings Platonic rationality down into the empirical realm. He elevates the truth-telling capacity of the material world, and thus the human body itself. This does not, however, lead him to an understanding of equality between the sexes. Quite the opposite. In contrast to Plato, Aristotle affirms both significant sexual difference and the natural superiority of men. This awards him the dubious honor of being, according to Allen, the “founder of the sex polarity position.”
Aristotle conceives of male and female as “contraries” or polar opposites within the same species. Such contrary differences, for Aristotle, can be explained only through privation—there must be some defect that prevents “one contrary from becoming its opposite.” Woman, then, is the one marked by the differentiating defect—she is different from man, who is the exemplar human being.
In Aristotelian terms, this differentiation occurs at the level of matter rather than form. Both sexes, then, share the same basic nature, but women are malformed or underdeveloped instantiations of that nature. Aristotle developed a clear—and enduring—association of man with form, and woman with matter. Because matter, in Aristotle’s schema, is pure passivity and prone to disorder and decay, this association carries a number of implications: women are less perfect, less spiritual, less rational than men, closer to the “many” than the “one.” Thus, men are by nature made to rule, and women by nature are made to obey.
Although Aristotle takes the body and its generative capacities more seriously than Plato, he fundamentally misunderstands the female role in human reproduction. For him woman contributes nothing active in the creation of a new human being; she is merely the space in which it happens. She is a passive receptacle; the generative seed comes entirely from the man.
In these two divergent (and highly influential) models, one can see the emergence of an underlying problem that endures even in contemporary gender debates: the apparent inability to conceive of sexual difference beyond hierarchies of value. The standard moves are to either follow Plato and downplay difference in order to affirm equality, or veer toward Aristotle and affirm both significant difference and—either implicitly or explicitly—one sex as superior to the other.
The first thinker to clearly articulate a third alternative between unity and polarity was the twelfth century abbess, mystic, theologian, composer, and physician Saint Hildegard of Bingen. She, according to Allen, is the “foundress” of gender complementarity. Hildegard’s theology is intensely incarnational: the material world is imbued with sacred significance and sacramental meaning. The human body is a microcosm of the cosmos, which Hildegard conceives as an ordered, harmonious whole. Her mystical vision of the universe is not a top-down hierarchy, but a cosmic egg with interconnected, nested layers—the earth at its heart.
Like Aristotle, Hildegard links man and woman with each of the four elements, but her associations are different and evoke new values. Aristotle’s cosmos is hierarchically ordered, down to the elements themselves, with fire being the highest, followed by air, water, and earth. He associates man with fire and air—man is higher, active, lighter, superior. Woman is linked to water and earth; she is lower, passive, heavier, inferior. Hildegard reorders this schema, connecting man with the highest and lowest elements—fire and earth—and woman with the two middle elements—air and water. In Genesis, after all, it is the man who is made from clay, not woman.
Hildegard’s theology, following sacred scripture, emphatically affirms that both woman and man carry the imago Dei, which endows each sex with equal dignity before God. While in her time female ovulation was still shrouded from human knowledge, Hildegard nonetheless elevates woman’s active participation in generation. Drawing on her experience as a physician, Hildegard provides a detailed account of human reproduction, in which man provides the seed, and woman’s body warms and livens the seed, strengthening it and readying it for the implantation of the soul by God. Because it is God alone who creates the soul, man and woman’s role in generation, in Hildegard’s understanding, is equally active and important, while remaining distinct.
On the level of virtue, Hildegard connects certain virtues to women, but unlike Aristotle, there is not a corresponding devaluation of those virtues in relation to masculine virtues. And, as Allen point out, in Hildegard’s thought, men and women are encouraged to develop in all the virtues:
Hildegard frequently argues that men ought to develop the feminine qualities of mercy and grace, while women ought to develop the corresponding masculine qualities of courage and strength. In this way, even though she designated particular qualities as masculine or feminine, a wholly integrated woman or man would have both aspects of their nature developed.
In all the categories of ontology, generation, wisdom and virtue, Hildegard stands apart from her male predecessors in her ability to uphold the two principles of difference and equal dignity. Plato dissolves difference into masculine unity, while holding onto at least a basic equality; Aristotle conceives of difference as hierarchical polarity. Hildegard’s complementarity affirms difference as a balanced, integrated harmony.
Hildegard’s incarnational vision of complementarity remained underdeveloped, however, as Western thought veered toward Aristotelian polarity in the thirteenth century, and then toward Cartesian dualism in the seventeenth century, wherein human identity was abstracted away from embodiment entirely. As Allen’s meticulous study shows, complementarity theory eventually branched into two distinct types: integral complementarity, which was prefigured by Hildegard, and fractional complementarity, which gained prominence in the Enlightenment, particularly among Protestant philosophers, such as Kant, Schopenhauer, Hegel, and Kierkegaard.
Fractional complementarity, in essence, conceives of man and woman as incomplete in themselves; they each represent one part or fraction of the fully integrated human being.
Woman was thought to provide half of the mind’s operations (i.e., intuition, sensation, or particular judgments) and man the other half (i.e., reason or universal judgments). These two fractional epistemological operations, if added together, produced only one mind. When the specifics of the engendered contributions were identified, these fractional relations often contained stereotypes of a hidden traditional polarity, with the man as superior to the female.
That last point is critical: complementarity, as it had become to be understood in Protestant thought, was really a refurbished polarity theory, because the “parts” of human nature associated with women were seen as inferior to those traits and dispositions associated with men. The result was that man could be a fully formed human being in his own right, but a woman was, by nature, incomplete without a man.
Allen’s framework enabled me to recognize that the so-called complementarity I had encountered in Evangelicalism is fractional at best, polarized at worst. Wild at Heart is a perfect example. In this pop-Christian book, man is the active one. He is wild, courageous, an adventurer. Woman, in turn, is passive, waiting patiently to be rescued, to be taken up into a heroic man’s story; she need not be wise or virtuous, merely beautiful and vulnerable. Man is, by nature, connected to the created order as a whole, whereas woman, by nature, is connected only to man. This view of gender relations, and others like it, is called “complementarian,” but there is a hidden polarity masquerading behind that term, as the man seems to be the representative human being, a whole person in his own right, whereas the woman is not. This vision of complementarity travels far afield from the balanced Hildegardian mutuality. For Eldredge, the man must have his own work, his own adventure, one in which a woman might share. But for Hildegard, opus alterum per alterum: man and woman are each the work of the other.
What, then, is the alternative? Is there any viable way through the Scylla and Charybdis of fractional complementarity and egalitarian neutrality? Allen argues that the incarnational vision of St. Hildegard reaches its full development in the 20th-century philosophy and theology of Saint John Paul II, who is properly the “founder” of this third way: integral complementarity. This theory of gender relations upholds the two principles of equal dignity and meaningful difference, while also adding a third principle: synergetic fruitfulness. Not only are man and woman whole persons, rather than fractional parts—their complementary difference is generative:
The integral complementarity model, already being articulated in some form in early personalism, argues that each man and each woman is a complete person, in an ontologically important sense. When they enter into interpersonal relations, the effect is synergetic; something more happens in relationship than parts of a person adding up to one person; something new is generated. While fractional complementarity can be represented by the formula ½ + ½ = 1, integral complementarity can be represented by the formula 1 + 1 = 3.
St. John Paul’s philosophy brings together two unlikely philosophical streams, Aristotelian Thomism and phenomenological personalism, which provide the foundations for integral complementarity. The Genesis cosmology, with its clear language of both man and woman as divine image bearers, contributes the principle of equal dignity. The Aristotelian thread in St. John Paul’s thought is not one of gender polarity, but rather the hylomorphic unity of body and soul. Aristotle rightly emphasized the importance of human embodiment, unlike Plato, and in this way, Aristotle contributes a framework for upholding the principle of significant difference between women and men. The human being, by definition, is a body-soul composite, and thus the body, including its sexed dimension, is integral to the whole person.
As Allen describes, St. John Paul’s “emphasis on wholeness” overcomes “the error of fractional complementarity.” Men and women are complementary as whole persons, as “the illustration of a biological, individual, personal and spiritual complementarity.” The fruitfulness of this complementarity includes procreation, but is not reducible to it—the creative synergy of male-female collaboration can foster new life and energy in the intellectual, spiritual, political, and professional realms as well.
The phenomenological stream in St. John Paul’s thought emphasizes the dimension of consciousness and lived experienced, but always in the context of embodied personhood. Man and woman, for St. John Paul, are “two ways of being a human person.” The terms “masculinity” and “femininity” are not confined to the body, synonymous with “male” and “female”; rather, they evoke the “personal consciousness of the lived experience of one’s body as a man or a woman.” These terms are thus rooted in sexed embodiment, but refer more holistically to the living, acting, person-in-the-world.
The common tendency to use masculine and feminine in reference to traits and behaviors, rather than persons, signals a fractional and Cartesian impulse—fractional, because certain traits and behaviors are associated exclusively with one sex or the other (e.g., emotions are feminine and rationality is masculine), and Cartesian because gender is associated with a disembodied trait rather than an embodied person. The widespread tendency to use those terms in precisely this way signals how deeply these fractional concepts are embedded in our understanding of gender.
St. John Paul, in contrast, “never attributed femininity to a man or masculinity to a woman,” because, for him, these terms signal “two complementary ways of being conscious of the meaning of the body.” Masculinity, then, is the lived consciousness of being and acting as a male human being, and femininity is the lived consciousness of being and acting as a female human being. This adds a sense of dynamism, freedom, and individual difference to gender complementarity, as there are many possible concrete ways of being a woman, or a man, in the world.
This approach also emphasizes the role of the intellect and will in living out one’s gendered personhood. Where fractional complementarity tends to see the person as determined by inherent and polarized masculine or feminine traits, the integral complementarity of St. John Paul envisions a whole person “going forth into the world and forming the self by personal acts.” And yet, this process of self-formation cannot occur apart from sexed embodiment, because of the hylomorphic principle: the human person is a body-soul composite. Bodily sex is constitutive of the whole person, not merely an inconsequential attribute with no inherent, pre-social meaning.
Embodiment, then, shapes one’s consciousness, but not in a totally deterministic way. Rather, the distinct generative capacities of men and women, toward which the whole body is ordered, give rise to certain dispositions or orientations that St. John Paul calls the masculine genius and the feminine genius. The female body is designed with an inherent potential to engender new life within; the human person has been entrusted to woman in a uniquely intimate and immediate way. Her genius is to be particularly attentive to the human person in whatever her realm of influence. The male body carries the potential to engender live without; like St. Joseph, he must make a willful act to accept and protect the mother and the child, even at cost to himself; he must choose to cross the distance that lies between himself and the vulnerable other, to reach out in love. The masculine and feminine genius are not oppositional, but analogical. They both reflect an orientation toward safeguarding and fostering human life, particularly in its most vulnerable forms, but in distinct maternal and paternal modes.
St. John Paul corrects a longstanding Aristotelian error by shifting an emphasis from menstruation to ovulation in considering a woman’s generative identity. His insights about how female embodiment can shape a woman’s consciousness and relational identity parallels, in many ways, the insights of French feminist theorists, such as Luce Irigaray and Hélène Cixous, who likewise argue that feminine subjectivity is shaped by the unique processes and potentials of the female body, such as ovulation and pregnancy, whether or not these culminate in literal motherhood.
Simplistically considered, St. John Paul’s language of masculine and feminine genius could be read as a fractional, rather than integral complementarity. But there are key distinctions at play. First of all, there is no laundry list of polarized traits associated exclusively to other sex or the other. The trait of nurturing, for example, could be part of living out a masculine genius, just as assertiveness could be part of enacting a feminine genius. Also, fractional complementarity tends to translate into prescriptive gender roles, whereas St. John Paul emphasizes the need for every area of life to be influenced by the genius of each sex—all spheres of human activity benefit from synergetic collaboration between men and women. Thus, it is left in the hands of the woman herself—in dialogue with her husband, if married—to determine her role, in terms of working within or beyond the home. This emphasis on woman “as an acting person” upends the Aristotelian notion of woman as passive in relation to man; both women and men have the capacity to choose how to be in the world, whether to act in a way that enables their respective geniuses to flourish.
I now consider myself a complementarian—but not in a fractional, Wild at Heart mode. Like Prudence Allen, I see integral complementarity as the best way forward for thinking about—and living out—gender. Alternative theories pull toward extremes that either depersonalize the body and efface sexual distinctiveness, or polarize the sexes and devalue one in favor of the other. Neither extreme is viable within a Christian understanding, which sees both man and woman as living images of God, an iconography made possible by their synergistic difference.
EDITORIAL STATEMENT: This essay is inspired by the "Concept of Woman Seminar," which explored the work of Sr. Prudence Allen. The event was hosted by the Notre Dame Office of Life and Human Dignity of the McGrath Institute for Church Life. The reflections about the seminar will be collected here as they are published.
 Jon Eldredge, Wild at Heart: Discovering the Secret of a Man’s Soul (Nashville: Thomas Nelson, 2001), 9.
 Ibid., pp. 17-18.
 Prudence Allen, The Concept of Woman: Volume I - The Aristotelian Revolution (Grand Rapids, MI: Eerdmans, 1997); Volume II – The Early Humanist Reformation (Eerdmans, 2002); Volume III – The Search for a Communion of Persons (Eerdmans, 2016).
 In the Republic, Plato refers to childrearing as one of the “pettiest of the evils” the guardian class would escape. Plato: The Complete Works, ed. John M. Copper (Indianapolis: Hackett, 1997), 1092.
 Ibid., 1088.
 A compelling argument can be made—and indeed, I would make it—that Platonic gender theory only appears to affirm equal dignity, because it demands that women adapt themselves to a masculine model, not unlike modern American feminism. In the Republic, although women are admitted to each class, the exemplars within each class are still men. And on a cosmic level, Plato has a clear hierarchy, as seen in the Timaeus.
 Allen, Vol. 1, 89
 Plato has this notion of the maternal as receptacle on a cosmic level in the Timaeus.
 Allen, Vol. 1, 292.
 Ibid., 298.
 Prudence Allen, “Man-Woman Complementarity: The Catholic Inspiration,” Logos: A Journal of Catholic Thought and Culture 9.3 (Summer 2006): 90.
 Ibid., 45
 Qtd. in Allen, Vol. III, 446
 Ibid.,1 445.
 Allen, “Man-Woman Complementarity,” 98
 Allen, Vol. III, 466.
 Qtd. in Allen, Man-Woman Complementarity,” 97.
 Allen, Vol. III, 450.
 Ibid., 469.
 Ibid., 455.