The Hypostatic Union: The Mutual Relationship of Nature and Person

In the Incarnation, as in the Trinity, the mystery of faith turns on the two fundamental notions of “Nature” and “Person” (or “Hypostasis”) — a person being simply a rational hypostasis. For the fuller background of these terms the reader should consult the treatise on the Trinity.¹

Nature and Hypostasis Distinguished

“Hypostasis” — and, for rational beings, “Person” — includes, beyond self-containedness and completeness, the further note of perseity: independent subsistence as a being distinct from every other being. “Nature” answers the question What?; “Hypostasis” answers the question Who? The Fathers and the councils express the relation between the two by saying that wherever several natures and persons are both involved, the persons are “one and another” while the natures are “one thing and another thing.” In the Trinity, the Father and Son are “one and another” (distinct Persons) but not “one thing and another thing” (they share one Nature); in Christ, we may distinguish “one thing and another thing” (two natures) but not “one and another” (He is only one Person). As St. John Damascene neatly puts it: “Hypostasis does not signify what or of what sort something is, but who it is… What differs in nature is called ‘one thing and another’; what is numerically distinct — that is, hypostases — is called ‘one and another.’ … Nature signifies what a thing is; hypostasis, this particular someone or this particular something.”²

Two conclusions follow. First, the heretical principle common to Nestorianism, Monophysitism, and Günther’s system — that there must be as many Hypostases as there are natures — is false on both philosophical and theological grounds. Second, neither philosophy nor theology can be satisfied with a merely logical distinction between nature and person; something more than a distinction of our own making is needed.

Real or Virtual Distinction?

In the Trinity there is at least a virtual distinction between person and nature. In man, some theologians hold the distinction may even be real. Two schools of thought divide on this point.

The Suarezian View

One theory, originating in the sixteenth century among theologians like Suarez, Vásquez, De Lugo, and Arriaga (and more recently Schiffini, Tepe, von der Aa, Schmid, and Urraburu), holds that no individual human nature possesses personality — independent subsistence — of and by itself; some further reality must be added to concrete human nature to make it a person. “This particular man” becomes a human person only through the addition of a further reality, on this view. But what kind of reality? Peter Hurtado and Quirós held, implausibly, that personality is a real substance nature can “put on or off like a hat,” separable from nature even in principle by divine power. Others, like Gregory of Valentia, treat personality as a “modal reality” admitting of one-sided but not mutual separation from nature: “By God’s absolute power, without contradiction, a singular nature could be preserved without any personality.”³ The chief argument for this view is that without some such detachable modal reality, it becomes unintelligible how Christ’s manhood can be a perfect human nature without being a human person. On this account, the Logos in becoming man assumed an impersonal humanity — impersonal for want of “hypostatic reality” — and communicated to it His own Divine Personality in its place.

The Scotist-Thomist View

A second, more plausible theory — held by Scotus and his school, and later by Molina, Petavius, Antoine, Mayr, Tiphanus, Franzelin, Stentrup, and Christian Pesch — holds that the distinction between nature and person in man is not real but only virtual: the same concrete object is, considered one way, “nature,” and considered another way, “hypostasis” or “person.” Advocates of this theory need not deny that personality is a real, positive mode rather than a mere negation (as the Suarezians sometimes mistakenly charge); they deny only that this positive mode is really distinct and separable from the concrete nature. That we habitually describe personality in negative terms (incommunicability, for instance) no more proves the concept itself is purely negative than defining “unity” as “indivision” makes unity a negative concept.

This theory, probably the true one, goes back to Theodore Abucara in the eighth century: “Is substance [nature] one thing, and hypostasis another?” he asks, and answers: “One and another, not as one thing and a different thing, but because ‘hypostasis’ signifies one thing and ‘substance’ another — just as a grain of wheat is called, and is, both seed and fruit, not as one thing and a different thing, but because ‘seed’ signifies one thing and ‘fruit’ another.”⁴ Applied to Christology, this theory explains the absence of a human person in Christ not by subtraction — removing some separable mode of subsistence — but simply by adding human nature, without its own personality, to the superior Hypostasis of the Logos.

Four Possible Relations, and Why Only One Is Orthodox

Abstractly, the relation between Christ’s Divinity and His humanity could be conceived four ways. Either person is united with person, yielding merely one “moral person” — the error of Nestorius. Or nature is blended with nature into a third being intermediate between the two — Monophysitism. Or the human personality, suppressing the Divine Hypostasis, absorbs the Divine Nature into a purely human hypostasis — an error so preposterous it has never found a defender. Or, finally, the Divine Person of the Logos, taking the place the human person would otherwise have occupied, unites itself to Christ’s human nature alone — the Catholic dogma of the Hypostatic Union.

Why does Christ’s human nature — like ours in everything but sin — receive its “personation” from the Logos rather than being its own human person?

The Scotist-Thomist Answer

Since the distinction between nature and person in man is only virtual, Christ’s humanity simply loses its would-be connatural personality by being assumed into, and absorbed by, the Divine Logos. In becoming the Logos’s own, Christ’s manhood loses its perseity — independent existence — by virtue of the union: it remains a complete nature, but is no longer a hypostasis in its own right, since it has become a constitutive element of a higher Hypostasis instead. Tiphanus, Franzelin, and Christian Pesch ground this reading in various Patristic texts, though Pohle notes these texts mostly stress either Christ’s full consubstantiality with man or the soteriological axiom “what was not assumed was not healed” — points not strictly at issue here, since the Suarezians do not deny that “hypostatic reality” is part of human nature; they merely hold that the personifying mode is, by its own inner character, incapable of being absorbed into a higher Hypostasis at all.⁵

A stronger argument for the Scotist-Thomist view comes from its ancient pedigree — Rusticus Diaconus, Theodore Abucara, and St. Maximus Confessor all held it, while the opposing (Suarezian) view is, as one of its own defenders admits, a comparatively modern invention.⁶ Abucara states plainly: “It is not enough for a nature, with its properties, to be composed together to generate a hypostasis; it must also not be a part [of some larger whole]. Since the assumed body-and-soul [i.e., the human nature] is a part of Christ, it is therefore not a hypostasis, but ‘hypostatic.’”⁷ The later Scholastics unanimously hold that Christ’s humanity would instantly reassume the character of a human person the moment it was released, hypothetically, from the Hypostatic Union — and not one of them suggests that it would need some special, additional form of subsistence to do so, which strongly suggests they saw personality as intrinsic to the nature itself, awaiting only its release from a higher union.

St. Thomas’s own position is harder to pin down — both sides of the dispute claim him. He agrees with Peter Lombard and Albertus Magnus that “separation gives totality to both parts… If it is asked what would confer personhood on [Christ’s humanity] which it did not have before, the answer is: the singularity, or incommunicability, it did not have before; for properly speaking, singularity is what makes a person out of a rational nature.”⁸ He further holds that Christ’s manhood lacks human personality not through any defect, but because something transcending human nature has been added to it.⁹ Where Thomas speaks of the “destruction” of Christ’s human personality, Pohle reads this as metaphorical rather than literal — Thomas himself, arguing against a claim wrongly attributed to Pope Innocent III (“the Person of God consumed the person of the man”), explains: “This ‘consumption’ does not mean the destruction of something that previously existed, but the prevention of something that could otherwise have been. For if the human nature had not been assumed by the Divine Person, it would have had its own personality; and it is in this sense — improperly speaking — that the [Divine] Person is said to have ‘consumed’ the [human] person, because the Divine Person’s union prevented the human nature from having a personality of its own.”¹⁰

An Objection Answered

One might object that Christ’s sacred humanity would be imperfect without the supreme prerogative of its own personhood. But the objection misses the point: Christ’s human nature is a person through the Divine Personality of the Logos, and it is a far higher prerogative for a created nature to subsist in a Divine Person than in a merely human one. As St. Bonaventure puts it: “The nature assumed in Christ is, by that very fact, more noble, because it is established in a more noble Person; hence its ordering to something more worthy, though it removes its own proper hypostatic standing, does not thereby remove its dignity.”

Notes