HUMAN NATURE, POTENCY AND THE INCARNATION
Alfred J. Freddoso
According to the Christian doctrine of the Incarnation, the Son of God is truly but only contingently a human being. But is it also the case that Christ's individual human nature is only contingently united to a divine person? The affirmative answer to this question, explicitly espoused by Duns Scotus and William of Ockham, turns out to be philosophically untenable, while the negative answer, which is arguably implicit in St. Thomas Aquinas, explication of the Incarnation, has some surprising and significant metaphysical consequences.
Christians profess that Jesus Christ is the eternal Son of God and yet that he is also like us in all things but sin. One metaphysical consequence of this belief--a consequence explicitly affirmed by the Church in response to heresies such as Apollinarianism, Monothelitism and Monophysitism1--is that Christ's individual human nature (his "human part," so to speak)2 is like every other individual human nature in its ontological constitution.
So, for instance, if Cartesian dualism is correct, then Christ' s individual human nature is an immaterial substance intimately but only accidentally related to a particular human body. On the other hand, if some version of Aristotelian hylomorphism is true, then Christ's individual human nature is a substance essentially composed of a particular body and a particular intellective soul. Corresponding conditionals hold for the various forms of materialism and emergentism that dominate the current philosophical scene, though at least some of these theories may well be incompatible with Christian doctrine taken as a whole.
Be that as it may, in this paper I wish to focus on a relatively specific metaphysical question concerning Christ's individual human nature, a question that arises regardless of which of the philosophical theories just mentioned is correct. Christians have traditionally affirmed that the Son of God freely took on a human nature and hence is only contingently a human being. But what of the converse? Is it also true that Christ's individual human nature is only contingently united to a divine person? Or, to put it more fashionably, using 'N' as a proper name of Christ's individual human nature: Is there a possible world w and a time t such that N exists at t in w without being united to a divine person?3 /28/
To get a deeper grasp of the issues surrounding this question, it will be useful to have at least a passing acquaintance with the key metaphysical concepts employed in the classical Christologies propounded by Thomas Aquinas, John Duns Scotus and William of Ockham. After providing this historical background in section I, I will go on in section II to examine a general metaphysical principle about individual human natures which Scotus and Ockham embrace without detailed argument and which has among its immediate consequences an affirmative answer to the question posed above. I will show that this principle, as well as a slightly weaker replacement, entails evident falsehoods and should thus be rejected in favor of a contrary principle, one which yields the thesis that Christ's individual human nature is necessarily such that it is united to a divine person. Finally, in section III I will formulate and examine what I take to be the strongest argument against my position. Given that my response to this argument is sound, two interesting corollaries follow for Christian metaphysics in general. First, the Christian metaphysician will have to countenance the possibility that some of a thing's necessary properties (those it has at any moment it exists in any possible world in which it exists) are not natural or essential properties (roughly, properties which it has simply by virtue of its nature or essence, including its individual essence). Second, the Christian metaphysician will be unable to subscribe to the widely accepted claim that any counterfactual conditional with a necessarily false antecedent is itself true. These two points and the connection between them will emerge more clearly below.
Since Aquinas, Scotus and Ockham will be my principal interlocuters, I will join them in presupposing the truth of a hylomorphic account of human nature. However, this presupposition is not crucial either to their arguments or to mine, all of which are easily translatable into idioms consonant with the competing accounts of human nature alluded to above.
According to the Christian faith, as defined in this instance by the great Christological Councils and mirrored in centuries of liturgical practice and theological reflection, Jesus Christ is truly God and truly man. More precisely, he is a single divine person, the eternal Word, in whom are united, whole and unmixed, a divine nature and a human nature--so that he is, to quote Chalcedon, "one with the Father in his divinity and one with us in his humanity."
In expounding this doctrine medieval theologians fashioned the technical metaphysical notion of a suppositum (or hypostasis), i.e. an independently existing ultimate subject of characteristics.4 The philosophically astute will detect at once that, so understood, the concept of a suppositum is remarkably akin to that of an Aristotelian primary substance or individual(ized) nature. Indeed, had /29/ it not been for the doctrines of the Trinity and the Incarnation, medieval Christian thinkers would never have been led to assert that suppositum and substance (or: individual nature) are distinct concepts. To speak now only of the Incarnation, Christ's individual human nature, i.e. the individual composed of a body and an intellective soul and united to the Son of God, is a paradigmatic Aristotelian substance, just the sort of thing Aristotle had in mind when he spoke of primary substances. Yet, because of its metaphysical union with and dependence upon the eternal Word, this nature is not the ultimate metaphysical subject of Christ's characteristics--not even of his "purely human" characteristics. So in this one instance, known to us only by divine revelation, we have a substance which is not a suppositum, a substance which is metaphysically "sustained" by something distinct from it. To complete the picture, a person is just a suppositum with an intellectual nature, i.e. a suppositum essentially endowed with intellect and free will.
In technical medieval terminology, then, Jesus Christ is a divine suppositum or person, the Son of God, who has freely "assumed" and now "sustains" an individual human nature. What's more, this human nature is united to the divine person "hypostatically," i.e. in such a way that properties had immediately by the human nature have the Son of God as their ultimate metaphysical subject--in a manner analogous to that in which many properties had immediately by a proper part of a whole have the whole itself as their ultimate metaphysical subject.
We might note in passing that the many contemporary philosophers who accept a basically Aristotelian (as opposed to, say, Lockean or Humean) account of substance will have little difficulty with the metaphysical analysis of a person as a suppositum with an intellectual nature. In fact, such philosophers are likely to be bemused by the assertion, sometimes heard issuing from the mouths of modern theologians, that the medieval notion of a person has been preempted or superseded in "modern thought.''5One can only conclude that those who make assertions like this have a disappointingly superficial and unduly selective acquaintance with the voluminous recent philosophical literature on substance, personhood and personal identity. The medieval conception of a person has not, to the best of my knowledge, been discredited in modern thought. To the contrary, I, like a great number of other philosophers--including many who care not a whit about theology--believe it to be essentially correct, and that is why I mean to take it very seriously in what follows.
One further matter must be clarified before we go on. While the medieval theologians I have mentioned all affirm that Christ is a person who is a man or human being, none of them affirms that he is a human person.6 There is a quite straightforward explanation for this: Aquinas, Scotus and Ockham evidently understand the term 'human person' in such a way that it stands for an individual human nature which is itself a suppositum and hence not sustained by any other /30/ suppositum. Given this understanding, to claim that Christ is both a divine person and a human person is to subscribe to the Nestorian heresy, according to which there are two distinct though closely related ultimate metaphysical subjects in Christ. Consequently, it is misleading to call Christ a human person if all one means to say is that he is a person who is a human being. On the other hand, there is no precisely analogous danger in calling Christ a divine person.
For the sake of convenience I will follow the tradition here by adopting this medieval differentiation between the terms 'human person' and 'person who is a human being.' This is, of course, largely a verbal matter, and so I do not care to take issue with those who would insist on using the first of these expressions as a convenient and admittedly natural abbreviation for the second. But to avoid misunderstanding in what follows, the reader should keep clearly in mind my concession to tradition on this point.7
We now have sufficient background to proceed to the business at hand. Aquinas, Scotus and Ockham all believe that Christ's human nature is a substance composed of a body and an intellective soul. They further agree--very plausibly, it seems to me--that in every case other than the Incarnation, an individual human nature by itself constitutes or just is a human suppositum or human person.8 That is, none of them believes that the term 'human person' refers to any "positive" entity over and beyond an individual human nature. (What sort of entity could it possibly be? A bare particular, perhaps?) And they all deny the quaint suggestion, made by some of their contemporaries, that a human person is composed of both positive entities (body and intellective soul) and "negative" entities, where the negative entities are thought of as yielding a human person when added as parts to a substance composed of a body and an intellective soul. (The temptation to posit such negative entities will become a bit clearer below.) The idea of a negative entity, our philosophers concur, is an absurdity. It follows from all this that the description of, say, Socrates as this individual human nature, i.e. the individual substance constituted by the union of this body with this intellective soul, is a complete description--one which encompasses every proper part of Socrates. So the human person Socrates has no parts which are not also parts of this individual human nature.
The foregoing remarks suggest a natural question: Given that some individual human natures are human persons while others, specifically Christ's, are not, what are the metaphysical conditions under which an individual human nature is a human person? The answer will presumably have something to do with whether or not the nature in question is sustained by a suppositum extrinsic to and distinct from it. In a moment I will explain Scotus' answer in some detail, /31/ but first we must attend to a relevant preliminary.
Scotus and Ockham, apparently unlike Aquinas, hold that the conditions which account for a nature's being a person or not being a person must be contingent to that nature.9 That is, on their view it cannot be a metaphysically basic fact that Christ's individual human nature is necessarily such that it is Christ's nature and hence not a person, or that a given individual human nature is necessarily such that it is the human person Socrates. But why not? Unfortunately, this is a question which, as far as I have been able to ascertain, Scotus and Ockham never address directly. Instead, they simply assume from the beginning that the following general principle is true:
(P) Necessarily, each individual human nature n is such that for any moment t at which n exists, either
(a) n is a human person at t, in which case
God has the power to bring it about that n is sustained by a divine
person (and hence is not a human person) at some time later than t;
Notice that (P) immediately entails the thesis that Christ's individual human nature is only contingently and possibly only temporarily sustained by a divine person. At the beginning of section III I will suggest a line of reasoning that may have led Scotus and Ockham to accept this thesis, but first I want to examine more closely (P)'s rather dramatic consequences for our understanding of human personhood.
Scotus gives a detailed and characteristically subtle answer to what I have called the natural question--an answer which Ockham evidently accepts in all its essentials.10 To get a clearer grasp of what Scotus says here, we should first define four technical terms expressing de re modalities. I will assume a basic familiarity with the distinction between metaphysical (broadly logical) and natural (physical) modality, noting only that I will follow a growing minority of contemporary philosophers in adopting a fundamentally Aristotelian, as opposed to Humean, conception of nature and natural law.11That is to say, I take the natural world to consist of a collection of agents (some non-free and others free with respect to at least some of their effects) endowed with causal powers and tendencies which in various situations may or may not be overridden by the powers and tendencies of other agents. Accordingly, natural laws are expressed not by universal generalizations (whether necessary or not) about events but rather by sentences in which characteristic powers and tendencies are ascribed to natural kinds, e.g., "Potassium ignites when exposed to oxygen." Such laws thus do not specify which events will or must follow upon which other events, but instead /32/ specify what behavior is naturally proper to a given class of agents under given circumstances. Notice that it could conceivably be a natural law that potassium ignites when exposed to oxygen even if no sample of potassium ever has or ever will ignite in the presence of oxygen--and this because of interference from other natural agents. (In such a case we would likely never discover the law in question, but that of course is another matter.) Given this philosophical conception of nature, the Christian philosopher can reasonably take the de re claim that it is naturally necessary for a created thing x to have a property P to be roughly equivalent to the claim that x is by nature such that it would have P if (i) it existed and (ii) God were to perform no "external" acts other than those required for the existence and ordinary causal interaction of created agents.12 Natural possibility, impossibility and contingency can then be characterized in the usual way.
With this admittedly sketchy background in mind, we can now proceed to our definitions. 'x' and 'P' are variables ranging respectively over individuals and properties:
x is in obediential potency with respect to P = df x is such that God has the power to bring it about that it has P.
x is in natural potency with respect to P = df It is naturally possible for x to have P.
x has a natural inclination toward P = df (i) It is metaphysically possible for x to be prevented from having P by the interference of some causal agent or agents, and (ii) it is naturally necessary for x to have the property Q, where Q is the property of having P unless prevented from having P by the interference of some causal agent or agents.13
x has a strong natural inclination toward P = df (i) x has a natural inclination toward P, and (ii) it is metaphysically impossible for x to be prevented from having P by the interference of any created agent or agents.14
In their discussions of the hypostatic union Ockham and Scotus presuppose, rightly I believe, that in order to be human Christ's assumed nature must be exactly similar to every other human nature in its natural potencies and natural inclinations as well as in its ontological constitution. We should probably consider this point to be simply a logical consequence of the doctrine that Christ' s assumed nature is like every other human nature in its ontological constitution. In any case, it serves as a constraint on any account of the metaphysics of the Incarnation.
In accordance with (P) above, Scotus begins by maintaining that every individual /33/ human nature is in obediential potency, but not in natural potency, with respect to being assumed and sustained by a divine person. That is, each human nature is, at every moment it exists, such that God can bring about its hypostatic union with a divine person--but God can accomplish this only by a special act which transcends the ordinary course of nature, an act which is praeter naturam.15
A human suppositum or person, Scotus continues, is just an individual human nature which is neither (i) actually sustained by an extrinsic suppositum such as a divine person nor (ii) naturally inclined toward being sustained by an extrinsic suppositum. Condition (ii) is not sufficient by itself, since even Christ's individual human nature, which is not a human person, lacks such an inclination. It, too, is only in obediential potency with respect to being sustained by an extrinsic suppositum. Condition (i) is not sufficient by itself because separated souls lack actual dependence on an extrinsic suppositum and yet are not human persons.16 Thus, both parts of this so-called "twofold negation," i.e. the negation both of actual sustainment by an extrinsic suppositum and of a natural inclination toward such sustainment, are required in order for an individual human nature to be a human person. The twofold negation is, as it were, a metaphysical function which takes individual human natures as arguments and yields human persons as values.
So a human person is just an individual human nature which satisfies the twofold negation. However, as emphasized above, it is a serious philosophical blunder to construe these negations as entities or res which count, along with body and soul, as proper parts of a human person. To the contrary, the negations are simply metaphysical conditions instantiated by each individual human nature which is a human person. Thus, when the Son of God assumes an individual human nature, no proper part of that nature or of any human person is destroyed. That is why Christ can correctly be said to have a complete human nature and thus to be truly a man. His human nature, just like every other, has as parts just a body and an intellective soul. In the Incarnation God simply brings it about by a special act that a certain individual human nature, exactly similar to every other in its ontological constitution and intrinsic inclinations, fails to satisfy the metaphysical conditions required for it to be a human person.
We should not underestimate the theoretical virtues of this account of the metaphysics of the Incarnation. First of all, Scotus is surely correct in maintaining that Christ's individual human nature lacks a natural inclination toward (and even a natural potency with respect to) possessing the grace of union with a divine person. In the same way, none of us is in natural potency with respect to that mysterious sharing in God's life which Christians call supernatural grace. God's blessing us with this grace is a special act which transcends the order of natural possibility. Second, on Scotus' account there can be no doubt that Christ's human nature is just like every other in its ontological constitution, natural /34/ inclinations and natural potencies. For if he is correct, then the Son of God could have assumed any arbitrarily chosen human nature, including yours or mine.
But this, unfortunately, is just the problem. Both Scotus and Ockham, as we have seen, presuppose from the beginning that any individual human nature which is a person is only contingently a person and possibly only temporarily a person. That is, the condition which we have dubbed the twofold negation is only contingently and possibly only temporarily satisfied by any individual human nature which in fact satisfies it. Each such nature can, by the power of God, be assumed by a divine person and thereby cease to be a human person. We have already seen enough to suspect that this is a truly astonishing claim. I will now try to confirm this suspicion with the help of a little story.
Suppose that we have before us an individual human nature, call it by the proper name 'B'. B, of course, is an individual composed of this body and this intellective soul. Suppose, further, that B satisfies the twofold negation and hence is an ordinary human person, say Socrates. As noted above, Aquinas, Scotus and Ockham all agree that B has all and only the parts, corporeal and incorporeal, which Socrates has. Calling B by the name 'Socrates' conveys only that B satisfies the metaphysical condition known as the twofold negation. Suppose further, as all three of our philosophers deem possible, that B has satisfied the twofold negation ever since it came into existence. It follows from this that B and Socrates had the same parents, came into existence together at exactly the same time and place, and have shared exactly the same history up to the present. To repeat, thus far we have made no assumptions which Aquinas, Scotus or Ockham would have the least reason to contest.
In the situation as described thus far, it is clear, I think, that we have more than enough evidence to warrant the claim that B is just identical with Socrates. Indeed, Ockham explicitly concedes that B and Socrates are now identical in every way ("omnino idem").17 Given their fondness for (P), however, the Franciscans, unlike Aquinas, must hold that the following extension of our story is metaphysically possible:
A divine person assumes B, at which point B ceases to satisfy the twofold negation and hence ceases, pace Nestorianism, to be a human person. Instead of being a human person, B is now simply a human nature sustained by a divine person. Hence, all the parts which once constituted a human person continue to exist in the same arrangement as before, even though the human person in question himself no longer exists. Nor is B in any way frustrated by the disappearance of this person. After all, B was only contingently related to him in the first place. Alas, poor human person! B's assumption by a divine person has apparently robbed him of an opportunity for eternal bliss. Could he perhaps enjoy it vicariously through B? But fret not, because fortunately for him, this is not the end of the story. Two weeks later, having enjoyed the 1984 World Series /35/ with his own eyes, the divine person breaks off his union with B, at which moment a human person (presumably the same one), having all and only B's parts, comes into existence.
This extension of our story captures just the sort of situation Ockham has in mind when he contends that the proposition 'A man is possibly assumed by the Word' is true.18 As long as B satisfies the twofold negation, it (he?) is identical with a man, viz., the human person alluded to above. But as our story is supposed to illustrate, the non-modal proposition 'B is assumed by the Word' is possibly true. And this is sufficient for the truth of 'A man is possibly assumed by the Word.' On the other hand, B ceases to be a man (i.e. a person who is a human being) at the moment at which it is assumed by a divine person---otherwise Nestorianism would be true. Hence, the non-modal proposition 'A man is assumed by the Word' is false, indeed necessarily false. So, Ockham concludes, the proposition 'A man is possibly assumed by the Word' is true, even though the proposition 'A man is assumed by the Word' is necessarily false.
There is no problem with the modal distinctions being employed here. As Ockham is wont to remind us, the proposition 'A white thing is possibly black' is true, even though the proposition 'A white thing is black' is impossible. Nonetheless, there is a problem here, a problem which lies not in Ockham's logic, but in his--and Scotus'--metaphysics.
Perhaps the best way to get at this problem is by posing the question: Where was Socrates during those two weeks, anyway? There are, it seems just two available answers. I will discuss them in turn.
(i) The first answer is that Socrates just is the human person we have been talking about and that, consequently, he simply did not exist during the two weeks in question. Instead, he ceased to exist when B was assumed by the divine person and resumed existing when B once again came to satisfy the twofold negation. So according to this first answer, even though B and Socrates were identical before B's assumption and even though no "positive entity" passed out of existence when B was assumed, nonetheless the human person Socrates did not exist in the period during which B failed to satisfy the twofold negation.
How plausible is answer (i)? Consider the following parallel story: Your son David is a typically active and imaginative six-year old. One day he solemnly announces that he is no longer David but is instead that exotic character known as 'Shirtless Sam.' You find this irritating for philosophical reasons among others, but having reached the brink of what promises to be just another fruitless metaphysical controversy, you cleverly obtain David's consent to the following compromise: He may always be called David, but he may also be called Shirtless Sam when he is both shirtless and silent. That is, 'Shirtless Sam' is an appropriate name for David when, and only when, he satisfies the twofold negation, shirtlessness and noiselessness. In an exhausting celebration /36/ of what he perceives to be a tactical victory over parental rigidity, David breaks into an hour-long routine during which Shirtless Sam alternates every two minutes between existing and not existing.
What are we to say of this all too likely story? Is it really the case that some entity is regularly alternating between existence and non-existence? Of course not. David, after all, is just the same person as Shirtless Sam. So given the obvious truth that David has the property of being necessarily such that he exists when and only when David exists, it follows by Leibniz's Law that Shirtless Sam has the property of being necessarily such that he exists when and only when David exists. Since David exists throughout the interval of time in question, it follows that Shirtless Sam exists throughout that same interval.
The loose and popular way of speaking I slipped into at the end of the story is engendered by the fact that David, though he is necessarily David and hence necessarily Shirtless Sam, only contingently satisfies the condition we had agreed to associate with the name 'Shirtless Sam.' So during the hour in question it was alternately appropriate and inappropriate, given this agreement, to call David by the name 'Shirtless Sam.' However, from this point about linguistic propriety it hardly follows that Shirtless Sam himself ever ceased to exist during that period.
Exactly the same considerations apply to the story of Socrates and B. Ockham and Scotus concede that B and Socrates are identical with one another at least before B's assumption by a divine person. But then, given Leibniz's Law, the following argument is impeccable:
(1) B is identical with Socrates.
It is important to notice immediately that the modality employed in (2) and (3) is de re, and not de dicto, metaphysical necessity. Likewise, it is important to notice that the term 'Socrates' in (3) and the first occurrence of 'B' in (2) fall outside the scope of the modal term. Thus, the soundness of the argument does not in any way depend on the assumption that the names 'Socrates' and 'B' are interchangeable salve veritate in all contexts; nor does it in any way depend on the assumption that 'Socrates' is a rigid designator rather than a shorthand substitute for a non-rigid definite description.19
Ockham and Scotus are, of course, firmly committed to (1)--and for sound metaphysical reasons. But, as the above argument shows, if Socrates is ever identical with B, then there is no time at which B exists but Socrates does not. (Indeed, if Socrates is ever identical with B, then there is no time in any possible world at which B exists but Socrates does not.) Of course, it may be that the /37/ name 'Socrates,' like the name 'Shirtless Sam,' is associated with the satisfaction of a twofold negation. So it may have been inappropriate during the two weeks in question to call B by the name 'Socrates.' Still, it does not follow from this point about linguistic propriety that Socrates did not exist when B failed to satisfy the twofold negation. Thus, answer (i) is irremediably deficient.
(ii) Our question concerned the metaphysical status of Socrates in the two weeks during which, as (P) assures us is possible, B was sustained by a divine person. As we have just seen, Scotus and Ockham cannot plausibly claim that Socrates did not exist during those two weeks. So they are left with answer (ii): Socrates is identical with B and hence did indeed exist throughout the time during which B was sustained by a divine person.
Unfortunately, however, answer (ii) fares no better than its predecessor. To see this, recall that Scotus and Ockham desire earnestly to avoid Nestorianism, and so they are forced to admit that B is not a human person during the period in which it is sustained by the divine person in question. But we now see clearly that B is just identical with Socrates during the same period. So Scotus and Ockham will also be forced to hold that Socrates is not a human person during that period. Socrates, in short, is only contingently a person. And, of course, since (P) is a perfectly general principle, Scotus and Ockham will also have to hold that every human person is, like Socrates in our example, only contingently a person.
It is easy to see, however, that this is an extraordinarily implausible response to our question. For if it is correct, then I could have existed without being a person--and, sad to relate, the same thing holds for you. To see this, keep Leibniz's Law fixed firmly in mind and consider the following generalizable argument which Socrates might propose:
(1*) I am identical with Socrates.
The proposed response accepts (1*) while rejecting (3*); so it must be rejecting (2*) as well. But this, I submit, is a manifest repugnancy which flouts our deepest convictions about ourselves and which the doctrine of the Incarnation can in no way be thought to sanction. Answer (ii) is, in short, utterly bereft of merit.
Let's recapitulate. If principle (P) is true, then the extension of the story of Socrates and B is metaphysically possible. But, as we have just seen, the extension of that story is metaphysically possible only if either (i) Socrates simply did not exist during the two weeks in question or (ii) Socrates, along with each of us, is only contingently a person. Both (i) and (ii), I have argued, are wholly unacceptable. So we should reject the claim that the extension of our story is /38/ metaphysically possible, and, consequently, we should also reject (P).
These very same arguments also undermine a weaker principle entailed by (P), viz.
(Q) Necessarily, each individual human nature is both (a) possibly such that it is a human person (and hence is not sustained by a divine person) and (b) possibly such that it is sustained by a divine person (and hence is not a human person).
Unlike (P), (Q) does not require that for any individual human nature n there be a possible world w such that n is a human person at some time in w but exists without being a human person at some other time in w. So (Q) by itself does not imply that the extended story of Socrates and B is metaphysically possible. Nonetheless, (Q) does imply that a slightly different story about Socrates and B is possible, one in which B is identical with Socrates in the actual world but is sustained by a divine person in some other possible world in which Socrates either does not exist or exists without being a person. But the arguments adduced above cast equally grave doubts on the claim that this alternate story is metaphysically possible. We have, then, what can only be deemed an extremely strong case for rejecting (P) and (Q) in favor of the contrary principle
(R) Necessarily, each individual human nature is either (a) necessarily such that it is a human person (and hence is not sustained by a divine person), or (b) necessarily such that it is sustained by a divine person (and hence is not a human person).
Consistently with (R) , we can then say that B is necessarily the human person Socrates, and that Christ's assumed nature is necessarily sustained by a divine person and hence necessarily not a human person. Moreover, we can deny that every individual human nature is in obediential potency with respect to being sustained by a divine person. So the extended story of Socrates and B correctly turns out to be metaphysically impossible, and human personhood correctly turns out to be an essential feature of human persons. Philosophically speaking, all is in order.
How is it that philosophers as gifted as Scotus and Ockham should have come to find themselves mired in the intellectual morass described above? What accounts for this embarrassing, not to mention fatal, showdown with Leibniz's Law? One possible explanation goes like this:
Scotus and Ockham apparently feel that the belief that Christ is truly human /39/ is jeopardized by Aquinas' contention that the assumed nature depends upon the divine suppositum for its very existence.20 They counter by insisting on that nature's metaphysical independence, claiming that it will continue to exist on its own as a human person if, as is possible, its union with the Son of God is broken off. This gives us the second half of (P). But at this point one might anticipate the objection that even this degree of independence is insufficient to guarantee that Christ is truly human, since every ordinary human nature necessarily exists on its own. Not so, reply Scotus and Ockham--every human nature is in obediential potency to being sustained by a divine person. And this, of course, gives us the first half of (P).
We have already belabored sufficiently the problems generated by (P) and its logical consequence (Q). The relevant question at this point is: Why think in the first place that the rejection of (P) and (Q) threatens Christ's claim on being truly human? What sort of argument might one muster for this opinion? The best I have been able to come up with is the following two-pronged argument aimed against my alternative position:
"Your position has it that Christ's assumed nature is truly human and yet that it both necessarily lacks its own personhood and is necessarily sustained by a divine person. But this set of claims cannot be consistently maintained.
"First, even though some properties had necessarily by a given individual (e.g., the property being Socrates) may not be shareable, it seems reasonable to believe that any shareable property had necessarily by any member of a given species or natural kind is also had necessarily by every other member of that species. But, according to you, every individual human nature except Christ's has necessarily the shareable property being a human person, whereas Christ's assumed nature stands alone in having necessarily the shareable property not being a human person. It follows that Christ's assumed nature is not after all truly human.
"Second, no individual human nature has a natural inclination toward the supernatural grace of (hypostatic) union with a divine person. On this everyone agrees, including you. Yet, according to you, Christ's assumed nature is necessarily united to a divine person; and it follows from this that Christ's assumed nature has a natural inclination, indeed a strong natural inclination, toward such union. So once again we reach the conclusion that Christ's assumed nature is not truly human."
I will deal with these objections in the order presented, with my response to the second building upon my response to the first.
Let's begin by formulating precisely the general principle invoked by the first objection:
(S) Necessarily, for any individual x, property P and natural kind K, if /40/ (i) x has P necessarily and (ii) x belongs to K and (iii) P is shareable, then for any individual y such that y belongs to K, y has P necessarily.
I will take "shareable" here to mean multiply exemplifiable, i.e. able to be exemplified simultaneously by many distinct individuals; and I will assume that natural kinds include only lowest-level species, so that animal, say, does not count as a natural kind, while human being and armadillo do.
In a moment I will delve a bit deeper into the question of why the first objection has the intuitive appeal it does. But it is important to see from the beginning that (S) as it stands has very little going for it.
First of all, consider the properties not being Socrates and being Socrates or a mother. Both are shareable, and yet each is had necessarily by some human beings and only contingently or not all by others.
Again, consider the world-indexed property being over six feet tall at some time or other in W, where W is, say, our world. This shareable property is had necessarily by the many human beings who in fact have it, and yet most human beings lack it altogether.
What's more, (S) fares extremely badly when we turn to various kinds of abstract entities. For instance, the property being false is shareable and is had necessarily by many propositions; yet other propositions lack it. Likewise, the set whose only members are Socrates and the number 26 has necessarily the shareable property having a human being as a member; yet countlessly many sets, even contingently existing sets, lack this property. Again, some natural numbers have the shareable property being odd necessarily; yet many natural numbers lack this property. And so on.
Moreover, even if we were to discover some (could it be other than ad hoc?) device for circumventing all the types of counterexamples just catalogued, (S) would still be, so to speak, epistemically non-mandatory. For many philosophers subscribe, seemingly without any epistemic impropriety, to the thesis that a natural substance's origins are essential to it. But this thesis is incompatible with (S). Consider, for instance, the property having Tom and Mary as parents, a property had by, let us say, Sara and Matthew. This is obviously a shareable property, and it is also a property which, if the philosophers in question are correct, Sara and Matthew have necessarily; yet most human beings lack it. In fact, given the phenomenon of twinning, even a property such as originating from sperm S and ovum O, where 'S' and 'O' are proper names, is shareable. Yet, if the philosophers in question are correct, this property, though lacked by almost all human beings, will be had necessarily by any human being who has it. Further, if origins are essential, then it may well be that other shareable properties intimately related to origins, e.g., certain sexual or racial properties, are (at least in some instances) also essential. But in that case all such properties /41/ will serve as counterexamples to (S).
So (S) is questionable, to say the very least. Nor is it easy to think of a more plausible candidate to play the role (S) plays in the first objection. Still, the objection itself has a certain initial attractiveness, and this may indicate that there is a more cogent objection somewhere in the neighborhood.
Let's begin by conceding that there is a sharp distinction between natural and supernatural properties, or, more accurately, a sharp distinction between properties that are natural to and properties that are supernatural to a given substance. It is no simple task to give a philosophically satisfying account of this important distinction, and I will not attempt to do so here. Nonetheless, Christian theology has traditionally made extensive use of it, and thus Christians in general might reasonably be expected to have at least a rough grasp of it. So, for instance, standard properties involving the generation, growth and development of human beings are natural to us; whereas our being saved from sin and offered a share in divine life is, according to Christian theology, a supernatural property, one which results from a special or extraordinary act of divine graciousness and which is thus wholly extrinsic to and beyond our nature and in no sense at all due to us or owed to us by virtue of our being human.21 Given the legitimacy of this distinction between natural and supernatural properties, we might formulate an objection analogous to the one just considered by invoking an intuition to the effect that every necessary property is natural rather than supernatural, or, alternatively, that no supernatural property is necessary. And then it would follow that if Christ's assumed nature is necessarily not a person, the property not being a person is natural to it--and for that reason the assumed nature cannot be truly human. So even if (S) is irremediably flawed, an alternative objection, somewhat similar to the first, might still be compelling.
Of course, even if we can make rough sense of the distinction between natural and supernatural properties, this distinction must be fleshed out more fully and more rigorously before our new objection can carry the weight its advocates intend it to. But suppose for the sake of argument that such a project were to be carried out to everyone's satisfaction. Even then, I believe, there would be an effective way of undermining this objection. For if Christian theology provides us with a reason to accept the distinction between natural and supernatural properties, it also furnishes us with grounds for doubting the intuition on which the objection rests. Specifically, it is not at all clear that the Christian faith supports or is even compatible with the thesis that no supernatural property is necessary.
For example, Christians generally hold that God is essentially gracious. But in that case it may very well be a metaphysically necessary truth that God offers supernatural grace and an opportunity for supernatural beatitude to every free creature whom he brings into existence. But if this is so, then each of us has /42/ necessarily a shareable property which can in no way be thought of as being natural to us. And, as far as I can tell, this in no way impugns either the claim that God makes this offer freely or the claim that creatures have no natural inclination toward such an offer. For God is presumably necessarily such that he is able not to create any free creatures at all and hence able not to offer anyone his grace; and his offering such grace to his creatures necessarily requires a special act on his part and is thus in no way due to them by nature.22 So it seems possible for us to have a necessary property which is not at the same time a natural property.
But now why can't something analogous be true of Christ's assumed nature? Why not say that Christ's assumed nature is truly human and yet that, in virtue of an extraordinary divine act performed in every world in which that nature exists, it has necessarily a shareable supernatural property which all other individual human natures lack, indeed lack necessarily, viz. the property not being a human person (or, alternatively, being sustained by a divine person)? I can see no convincing reason, philosophical or theological, for not saying this. Perhaps someone will feel inclined to resist the suggestion that such a nature is truly human. But why exactly? Is there a metaphysical impossibility lurking about? If so, exactly where?
Notice, I am not claiming here that God in any sense brings it about, whether freely or otherwise, that Christ's assumed nature is necessarily not a person or is necessarily sustained by a divine person. Nor, letting 'N' be a proper name of the assumed nature, am I claiming that God brings it about that the propositions If N exists, then N is not a person and If N exists, then N is united to a divine person are metaphysically necessary. To the contrary, the arguments of section II show that if N is in fact united to a divine person, then it is metaphysically impossible in itself, as it were, that N should exist without being so united or without being a non-person. To be sure, those same arguments also show that God cannot create N unless he also brings it about that N is united to a divine person and is thus not itself a person. But, as far as I can tell, it does not follow from this that God thereby brings it about that N is necessarily not a person or that either of the propositions alluded to above is necessarily true.
Consider the following somewhat analogous case. Suppose that in my capacity as director of graduate studies I bring it about in our world, call it 'W', that Michael is admitted to graduate school. There are, of course, familiar arguments to show that if Michael is admitted to graduate school in our world, then (i) Michael has necessarily the world-indexed property being admitted to graduate school in W and (ii) the proposition If Michael exists, then he has the world-indexed property of being admitted to graduate school in W is necessary. Yet few of us would be tempted to claim that by bringing it about that Michael is admitted to graduate school I bring it about that Michael has the property in /43/ question necessarily or that the proposition in question is necessarily true. So even though it follows from something I do that Michael has a certain property necessarily and that a certain proposition is necessarily true, still I do not bring it about that Michael has that property necessarily or that that proposition is necessarily true. Likewise, even though it follows from something God does that N is necessarily not a person and that If N exists, then N is not a person is necessarily true, still God does not bring it about that N has that property necessarily or that that proposition is necessarily true.23
Let's now move on to the second main objection. My response to it, in a nutshell, is that from the fact that Christ's assumed nature is necessarily sustained by a divine person, it does not follow that that nature has a natural inclination to such sustainment. My reasons for thinking this have already been adumbrated. But I now want to develop this claim in a slightly different way.
We can, I take it, get a handle on the notion of a natural inclination by the use of counterfactual conditionals. For instance, suppose that I was correct in suggesting that each of us is necessarily such as to be offered a share in divine life. In that case presumably (a) it is true that if I existed but God did not by a special act offer me a share in divine life, then I would not have an opportunity to share in that life, and (b) it is false that if I existed but God did not by a special act offer me a share in divine life, then I would still have the opportunity to share in that life nonetheless. And I take the conjunction of (a) and (b) to entail that I lack a natural inclination toward having an opportunity to share in divine life and, indeed, that I have a strong natural inclination toward not having such an opportunity. Likewise, the proposition that Christ' s assumed nature lacks a natural inclination toward union with a divine person (and, indeed, has a strong natural inclination toward being a human person) is presumably entailed by the conjunctive claim that
(4) If Christ' s individual human nature existed but were not, by a special act of God, sustained by a divine person, then it would not be sustained by a divine person and hence would be a human person
is true, while
(5) If Christ' s individual human nature existed but were not, by a special act of God, sustained by a divine person, then it would nonetheless be sustained by a divine person and hence would still not be a human person
is false. Moreover, this claim seems perfectly reasonable to me--no less so than in the case mentioned above. But to many philosophers it will seem sheer folly for me to affirm (4) and deny (5). For my position includes the claim that the antecedent shared by (4) and (5) is necessarily false. And, I will be told, any /44/ counterfactual conditional with a necessarily false antecedent is true, indeed necessarily true. So how can I claim that (5) is false?
My response is that even if we limit ourselves to "purely philosophical" cases, we will find plenty of reasons for having doubts about the semantic principle just enunciated, despite its current popularity. Let me begin with the following three propositions, each of which has an impossible antecedent:
(6) If Socrates were a donkey, then some man would have
I can speak only for myself, but while I waver on (6) and (7), I find myself very strongly, almost overwhelmingly, inclined to believe that (8) is false. Of course, an ingenious philosopher such as David Lewis might have some success at eroding my confidence in this belief. But even upon reflection I find myself firmly believing that the falsity of (8) should serve as a datum for and constraint upon any attempt to construct a comprehensive semantics for subjunctive conditionals.
When I have made this suggestion in conversation, my interlocuters have sometimes objected that in order to be consistent, I should have similar doubts about the commonly accepted thesis that a necessarily false proposition strictly (as opposed to counterfactually) implies any proposition at all. However, I fail to see why this is so. For the objection has force only if the following principle is true:
(T) For any propositions p and q, if p strictly implies q, then p counterfactually implies q.
And while I acknowledge that (T) is plausible if 'p' stands just for propositions that are possibly true, it is precisely when we allow 'p' to stand for necessarily false propositions that doubts begin to arise--and with good reason, I believe.
Let me elaborate. To say that p strictly implies q is to say that it is metaphysically impossible that p be true and q false--a condition trivially satisfied if p is itself necessarily false. So it would be foolhardy indeed to doubt that a necessarily false proposition strictly implies any proposition you please.
However, as I indicated above, there are many propositions like (8) whose falsity is intuitively obvious to at least some of us. And if this appeal to intuition seems a bit too tawdry, we might also recall that many important and perhaps convincing arguments in the history of philosophy (and, so I am told, in the history of mathematics) are at least implicitly of the following form: "p is necessarily false, but if per impossibile p were true, then...". Now the proponents of such arguments do not ordinarily feel entitled to fill in the blank with just /45/ anything at all. To the contrary, their arguments are successful only if some ways of filling in the blank yield falsehoods.
An example might be illuminating here. Aquinas believes that the proposition 'God exists' is necessarily true, and hence that the proposition 'No intellects exist' is necessarily false. Yet in De Veritate q. 1, art. 2 he argues, quite intelligibly, that truth consists in a certain relation between world and intellect, so that if per impossibile there were no intellects, then even if other things existed, there would be no truths. Now one might, of course, disagree with this thesis, perhaps because of its anti-realist overtones. But it would clearly be impertinent to trivialize Aquinas' argument by insisting that it is also true that if per impossibile there were no intellects, then there would be infinitely many truths--and this simply because a necessarily false proposition counterfactually implies anything you please. Or at least let me claim this much: Anyone who agrees that such a response would be fatuous, demeaning or otherwise inappropriate ought to have doubts about (T) similar to mine.
I do not expect that the above considerations will move every sane reflective person. But neither do I deem them frivolous or unabashedly self-serving. (T) may be true, but its epistemic status hardly rivals that of, say, Leibniz's Law.
To return to the matter at hand, I take it to be at least reasonable to claim that (4) above is true while (5) is false. So it is reasonable to believe that even though Christ's assumed nature is necessarily sustained by a divine person, it nonetheless lacks a natural inclination toward union with a divine person and has a strong natural inclination toward being a human person. Hence, Christ's assumed nature does not differ from other individual human natures in any of its natural inclinations. It differs fr6m the others only in that it has necessarily a supernatural property which the others lack necessarily.24 Still, if per impossibile that nature were to exist without being sustained by a divine person, then it would, like other human natures, be a human person with all the foibles thereof. (This suggests that what I have said here may shed some light on the traditional problems associated with Christ's knowledge and sinlessness.)
I conclude, then, that Christ's individual human nature is necessarily such that it is sustained by a divine person. Given the alternative, viz. a commitment to (P) or at least (Q), the Christian philosopher really has little choice but to accept this claim. However, the situation is not as grim as this last remark might lead one to think. For as I have tried to show, the claim in question is susceptible to a reasonable and philosophically interesting defense.25
What positions does (or would) Aquinas hold on the various issues broached /46/ here? The answer to this question is not altogether clear, but I have assembled a group of passages from Aquinas' works that will at least provide some clues.
As I mentioned above, Aquinas denies in various places that Christ's assumed nature has the sort of independent existence characteristic of individual natures which are themselves persons or supposita. In technical terminology, the assumed nature lacks its own (substantival) esse. (See, e.g., Summa Theologiae III, q. 17, a. 2, responsio and Quaestiones Quodlibetales IX, q. 2, a. 2, responsio.) Still, St. Thomas does clearly hold that Christ's human nature has a natural inclination toward self-subsistence. This claim, entailed by the conjunction of (4) and the negation of (5), is fully in accord with the position defended above and is propounded by Aquinas in the following three passages, the last of which begins with an objection to the claim that in Christ there is just one person and ends with Aquinas' response:
"For if the human nature were not assumed by a divine person, then the human nature would have its own personhood...By this union the divine person prevents the human nature from having its own proper personhood." (Summa Theologiae III, q. 4, a. 2, ad 3)
"Suppose, however, that the humanity were to be separated from the divinity. Then the humanity would have its own esse, distinct from the divine esse. For nothing prevented it from having its own proper esse except for the fact that it did not subsist on its own (per se)." (Quaestiones Quodlibetales IX, q. 2, a. 3, responsio)
"10. Moreover, each thing is resolved into those
things of which it consists. Therefore, assume that per impossibile
the Word of God were to lay down the human nature. In that case, the human
nature would have its own proper hypostasis and suppositum. Therefore,
even while it is still united, it has its own proper hypostasis and person.
So it is not the case that here there is just one hypostasis or one suppositum...
Notice that Aquinas does not dispute the presupposition, made in the above objection, that it is impossible for the Son of God to break off his union with the assumed nature. It is, in fact, beyond dispute that Aquinas rejects principle (P) above. He holds both (a) that it is metaphysically impossible that some /47/ preexisting nature be assumed by a divine person and (b) that it is metaphysically impossible for any human nature once sustained by a divine person later to exist on its own. In addition to the two passages cited in note 6, the following passages serve as evidence for the claim that Aquinas held both (a) and (b):
(a) "Now since the Word assumed the human nature
into the unity of a person...it was necessary that the human nature not
exist before being united to the Word.
"A person is not presupposed in the human nature for the assumption...For if it were presupposed, then either it would have to be corrupted, in which case it would be assumed without effect; or else it would have to remain after the union, in which case there would be two persons, the one assuming and the other assumed--which is erroneous." (Summa Theologiae III, q. 4, a. 2, responsio)
(b) "That which is given by God's grace is never revoked without some fault...But the grace of union by which the divinity is united hypostatically to Christ's flesh is much greater than the grace of adoption by which others are sanctified. Also, it is more permanent by its nature, since this grace is ordered toward a hypostatic union, whereas the grace of adoption is ordered toward an affective union. Yet we see that the /48/ grace of adoption is never lost except through sin. Therefore, since there was no sin in Christ, it was impossible that the union of the divinity with his flesh should be dissolved. (Summa Theologiae III, q. 50, a. 2, responsio)
"Since the Word of God was not separated in death from his body, much less was he separated from his soul..." (Summa Theologiae III, q. 50, a. 3, responsio)
Some commentary is called for here. Aquinas believes that it is not within Christ's power to sin and, further, that it is metaphysically impossible for a divine person to sin, even via a created nature. Thus, the arguments from the last two passages can plausibly be extended to yield the conclusion that it is metaphysically impossible that some created nature should at one time have the grace of union with a divine person and then at some later time lack this grace and exist on its own instead. Clearly, then, Aquinas rejects the second half of (P) . The first passage, from the Summa Contra Gentiles, makes it equally obvious that he rejects the first half of (P).
But what of (Q)? Does Aquinas think that it is possible for one and the same human nature to be united to a divine person in one possible world and to exist on its own in some other possible world? Here things get a bit murkier. Nonetheless, it seems natural enough to apply the sorts of arguments found in (a) against the weaker principle (Q). What Aquinas argues is that you simply cannot have the same nature existing on its own at one time and then being sustained by a divine person at some later time. That is, identity through time in such a case is ruled out by the metaphysics of personal or hypostatic union. Even if some preexisting nature is as similar or as closely related as you please to the nature which is assumed, still on Aquinas' view there must be two distinct natures here. But if he believes this, then it is difficult to see how he could accept (Q). For exactly the same considerations that apply across times seem also to apply across possible worlds, so that no amount of similarity across worlds is sufficient for the identity of natures n and n* if n exists on its own and n* does not.
So there is at least some reason for thinking that Aquinas would reject (Q) as well as (P) . But if this is so, then it is not altogether rash to think that he might in addition be kindly disposed toward (R). What, after all, are the alternatives?
2. I purposely use the term "part" here, since, as I have argued elsewhere, our best hope for conceptualizing the metaphysics of the Incarnation may well lie in the use of a mereological model. 'See my "Logic, Ontology and Ockham's Christology," The New Scholasticism 57 (1983): pp. 293-330, esp. pp. 302-312.
3. In what follows modal terms are always meant to express metaphysical (broadly logical) modalities unless otherwise indicated. I mention this because I will have occasion in section II to define three technical terms by reference to natural (physical) necessity and possibility. So it is only when I use those terms (to wit, 'natural potency', 'natural inclination' and 'strong natural inclination') that I mean to be invoking natural instead of metaphysical modalities.
....a suppositum is (A) a complete being, (B) incommunicable by identity, (C) not apt to inhere in anything, and (D) not sustained by anything. (A), i.e. 'complete being', rules out any kind of part, be it essential or integral, since neither kind of part is a complete being. (B) rules out the divine essence, which, though it is a complete being, is nonetheless communicable to the divine persons by identity and thus is not a suppositum. For a suppositum is incommunicable by identity. (C) rules out every accident, whether it inheres in anything or not. (D) rules out the nature assumed by the Word, since it is sustained by him.
This passage is from Quodlibeta Septem IV, q. 7, found in a critical edition in J. Wey, ed., Ockham: Opera Theologica (hereafter: OT), vol. IX (St. Bonaventure, NY: Franciscan Institute Press, 1980), pp. 328-329. (The above translation and all the others which appear in this paper are my own.) Matter and form are essential parts. Also, Ockham holds that in the Eucharist accidents exist without actually inhering in anything, but that they nonetheless retain their inclination or aptitude to inhere in something.
...nothing can be done to conceal the real shift between the ancient and the modern concepts of 'person'. Classical theology spoke of a rational being existing in its own right. It failed to express interpersonal relations in its account... Modern thought latches onto self-awareness, freedom and--in a particular way--intersubjectivity as key characteristics of a personhood. We become persons in dealing with other persons, sharing a common language and experiencing a common history. Human persons exist only in the plural. We repeat the traditional word ('person') at our peril. It has changed its meaning. (Gerald O'Collins, S. J., What Are They Saying About Jesus? [New York: Paulist Press, 19771, p. 8. )
Such talk may simply reflect a harmless misunderstanding, since the medieval account clearly entails that persons have natures intrinsically disposed toward self-awareness, free action and inter-personal relations. Or perhaps the writer is innocently confusing a metaphysical analysis of personhood with a psychological account of paradigmatic personhood or personal flourishing. However, the implications are a bit more disturbing if we take statements like the above as serious attempts to /50/ state sober metaphysical truths. Is the writer claiming, for instance, that self-awareness and the power to act freely and engage in meaningful intersubjective relationships are metaphysically necessary conditions for being a person? If so, this bit of news will not be welcomed by those many human beings who happen to be mentally retarded, insane, senile, comatose or, for that matter, sound sleepers--not to mention, more poignantly in view of the fact that the author is a Catholic priest, fetuses and newly born infants. Again, in claiming that "we become persons in dealing with other persons," does the author really intend to propose the metaphysical thesis that one and the same individual can in the normal course of things first be a non-person and then be a person? Of course, if the assertion that human persons exist only in the plural is meant to express a metaphysical necessity, it will at least have the virtue of bringing comfort to anyone beset by an inordinate fear of being the sole survivor of a nuclear holocaust. But such an assertion is itself unlikely to survive the devastation wrought by careful philosophical scrutiny.
Note also that in the Christian theological tradition the concept person is unalterably and irreducibly metaphysical. That is to say, whether or not a given entity satisfies this concept is a matter wholly independent of anyone's beliefs, attitudes, prejudices, etc. So Christians have a special reason for resisting the claim, sometimes heard in contemporary moral debates, that person is an "evaluative" rather than a metaphysical category--the implication being that an entity x is a person only if the rest of us (or, perhaps, those in charge or those in the know) consent to treat x in the special way associated with personhood.
6. Those familiar with the Christological writings of Aquinas, Scotus and Ockham know that the three of them normally speak of Christ as a divine person subsisting in or sustaining a human nature or, more neutrally, as a person subsisting in two natures. In addition, I have found two places in which Aquinas actually denies by implication that Christ is a human suppositum or human person. In both cases he is arguing that Christ assumed his human nature from the very first moment of its conception, so that the nature was not itself a suppositum before the union:
If the Word of God had not assumed the human nature from the first moment of its conception, then the active power in generation would, before the union, have ordered its activity toward an individual of human nature, i.e. toward a human hypostasis or person...So it would not have been proper for the Word of God to assume the human nature after its conception rather than at its very conception. (Summa Contra Gentiles IV, chap. 43 )
But in the human generation of Christ the ultimate goal of the generation was the union with a divine person, and not some human person or hypostasis which was supposed to be constituted. (Summa Contra Gentiles, IV, chap. 45)
7. There is, however, a related point that is substantive rather than verbal. It would be a grave error to think that in making the metaphysical assertion that Christ's human nature lacks its own personalitas (personhood), the medievals thereby meant to make the psychological claim that Christ lacks a human personality, where the English word 'personality' is taken in the usual way to connote a configuration of character traits and temperament. They meant no such thing, and even so much as to suggest otherwise (as some have) is disingenuous or at best a sure sign of deficiency in one's ability to translate from Latin into English.
8. See, e.g., Aquinas, Summa Theologiae III, q. 2, a. 2, ad 2, and III, q. 2, a. 5 ad 1; Duns Scotus, Quaestiones Quodlibetales, q. 19, found in English translation in John Duns Scotus, God and Creatures: The Quodlibetal Questions, edited and translated by F. Alluntis and A. B. Wolter /51/ (Princeton, NJ: University Press, 1975), p. 429 (para. 19.42), pp. 432-430 (para. 19.55-19.72), and pp. 438-439 (para. 19.81); and William of Ockham, Quodlibeta Septem V, q. 10 (OT, vol. IX, p. 520). While Scotus and Ockham explicitly identify the singular substance (or nature) with the suppositum in the case of ordinary human beings, Aquinas instead claims that the union of matter and form constitutes a suppositum or person in such cases, and that this person "subsists in" the nature. (See Summa Contra Gentiles IV, chap. 49.) I will ignore this difference in what follows.
9. Some of the clearest indications of this are found in the following places: Scotus, God and Creatures, p. 433 (para. 19.62) and p. 435 (para. 19.69); Ockham, Quodlibeta Septem IV, q. 7 (OT, vol. IX, p. 329); Ockham, Reportatio III, q. 1 (OT, vol. VI, edited by F. Kelly and G. Etzkom [St. Bonaventure, NY: Franciscan Institute Press, 1982], pp. 28 and 31). In the Appendix I will cite passages from Aquinas's writings to support my contention that Aquinas explicitly rejects (P) .
10. See Duns Scotus, God and Creatures, pp. 432-442 (para. 19.55-19.92). For the main outlines of Ockham' s theory see his Reportatio III, q. 1, (OT, vol. VI, pp. 3-42), and his Quodlibeta Septem, IV, q. 7 (OT, vol. IX, pp. 328-337).
11. What follows is the barest sketch of an Aristotelian conception of nature--a sketch meant only to facilitate for present purposes an understanding of the medieval notions of natural potency and natural inclination. For a fuller account of an Aristotelian conception of nature see Peter Geach's essay on Aquinas in Three Philosophers (Ithaca, NY: Cornell University Press, 1961), and also R. Harre and E. Madden, Causal Powers (Totowa, NJ: Rowan and Littlefield, 1975). For an excellent discussion of Christian conceptions of nature and the effect of an Aristotelian view of nature on our understanding of miracles, see Stephen Bilynskyj, God, Nature and the Concept of Miracle (Ph.D. Dissertation, University of Notre Dame, 1982).
12. I hope to work this suggestion out in greater depth elsewhere. For now it is sufficient to keep in mind that from the fact that it is not naturally possible for x to have P it does not follow that x does not have P or that it is metaphysically impossible for x to have P. Likewise, from the fact that it is naturally necessary for x to have P it does not follow that x in fact has P or that it is metaphysically necessary for x to have P. However, in the first case x's having P can be brought about only by some agent (presumably God) acting beyond or contrary to natural law, and in the second case x's not having P likewise requires a special divine act. These considerations will become important below.
13. So, for instance, potassium has a natural inclination toward the property igniting in the presence of oxygen. Thus if a given sample of potassium does not ignite in the presence of oxygen, this fact requires an explanation in terms of the causal influence of other operative agents. I should mention in passing that while my definition of a natural inclination may appear at first glance to make it a somewhat stronger notion than Scotus has in mind, I am prepared to argue that this appearance is deceptive. However, even if I am mistaken on this point, the particular inclinations discussed below turn out to be natural inclinations on either account.
14. The notion of a strong natural inclination is not used explicitly by Scotus, though it is intimated by what he says. Notice that x has a strong natural inclination toward P only if it is naturally necessary for x to have P. For God's preventing x from having P would require a special act over and beyond those acts involved in his creating and conserving natural agents and in his concurring with their characteristic causal activities.
15. See Scotus, God and Creatures, pp. 434-435 (para. 19.63-19.69). While both Scotus and Ockham agree that God's special act would not be contra naturam, i.e. contrary to (as well as beyond) nature, they disagree on exactly why this is so. Scotus contends that every human nature, including Christ's, has a natural inclination to be self-sustaining and hence a person. On his view /52/ the fact that Christ's assumed nature is at least possibly such that it is a human person is sufficient to guarantee that that nature is not "frustrated" by the fact that it never has been and never will be a human person. Ockham, by contrast, seems to believe that if Christ's assumed nature had a natural inclination to be a human person, then it would be contra naturam for it to exist without ever being a human person. So he denies that the assumed nature has a natural inclination to be a person. As a result, he must also deny than any other human nature has a natural inclination to be a person. Instead, he claims, every such nature is merely in "neutral potency" with respect to being a human person. See Reportatio III, q. 1 (OT, vol. VI, pp. 37-38) and Quodlibeta Septem IV, q. 7 (OT, vol. IX, p. 336). Ockham is thus led to the awkward (and probably inconsistent) conclusion that while it is naturally impossible for any given human nature to be united to a divine person, it is not naturally necessary f6r it to be a human person. However, I will not press this criticism of Ockham here, since my present aim is to show that absurdities follow from the assumptions which Scotus and Ockham hold in common.
16. Scotus apparently thinks of a separated soul, which is the form of an individual human nature, as a deviant instance of a human nature. (It is helpful here to recall that in the Metaphysics Aristotle identifies substance sometimes with the whole composite of form and matter and sometimes just with the form itself. And there may be good philosophical reasons for maintaining this ambivalence. See Michael J. Loux, "Ousia: A Prologomenon to Metaphysics Z and H," History of Philosophy Quarterly, 2 (1985): pp. 241-266.) Since the soul lacks a body, it is not actually dependent on anything distinct from itself. Yet it retains its natural inclination to be dependent on an extrinsic suppositum, viz. the nature composed of it and its body.
19. These points are, I think, fairly obvious. I mention them explicitly only because one reader of an earlier version of this paper claimed that the argument under consideration begs the question by presupposing that 'Socrates' is a rigid designator. Clearly, however, the argument presupposes no such thing. It would still be sound even if we substituted 'the teacher of Plato' or 'B, which satisfies the twofold negation' for 'Socrates' throughout. I also want to insist that this argument is distinct from and far stronger than the superficially similar arguments that Ockham considers and responds to in Quodlibeta Septem IV, q. 7 (OT IX, pp. 331-335: Instantiae 1 & 2 and the responses to them. )
20. Aquinas denies that Christ's assumed nature has its own esse or act of existence. I cannot here get into all the ramifications of this claim, but it is at least clear that Aquinas thinks (P) (and probably (Q) as well) to be false. I will substantiate this claim in the Appendix.
21. By a special or extraordinary act I mean one which goes beyond God's creating and conserving the individual in question and also beyond his cooperating or concurring with the operations characteristic of natural agents in general.
22. In order for this last point to be true it is not required, I would claim, that my existing in a "purely natural" state be metaphysically possible. All that is required is that the first of the following counterfactual conditionals be true and the second false:
If God were to create me but not offer me his grace, then I would exist in a purely natural state.
If God were to create me but not offer me his grace, then I would still have an opportunity to share that grace and thus would not exist in a purely natural state.
Below I will defend the claim that counterfactuals with metaphysically impossible antecedents can /53/ differ in truth value.
If p entails q and S has the power to make p true, then S has the power to make q true.
For a brief discussion of this and related principles, see section II of my "Accidental Necessity and Power over the Past," Pacific Philosophical Quarterly 63 (1982): 54-68.
24. This point suggests an objection which medievals would be likely to raise and which a contemporary philosopher might well sympathize with. The medieval way of putting it would be to say that no nature can be "permanently" frustrated. A more contemporary way of putting it would be to say that if it is naturally necessary for x to have P, then there is some time at which x has P or at least some possible world in which x has P. "But on your account," my opponent continues, "it is naturally necessary for Christ's assumed nature to have the property of being a human person, even though that nature lacks that property at any time it exists in any possible world!" The objection as thus stated is little more than an exclamation, but perhaps it becomes more forceful when put in the form of the following question: "What could it possibly mean to say that it is naturally necessary for a thing to have a property when it is metaphysically impossible for it to have that property!?"
As I explained above, I take the claim that it is naturally necessary for x to have P to be roughly equivalent to the claim that x is by nature such that it would have P if it existed and God were to perform no external acts other than creating and conserving natural agents and concurring with their characteristic causal operations. Given this rough equivalence, along with what I have just claimed about counterfactuals with impossible antecedents, it simply follows that x's having P may be naturally necessary though metaphysically impossible. In the absence of some further elaboration of the objection, it is difficult to know what more to say in response.
Of course, I full well realize that my position does not sit well with the standard possible worlds treatments of natural necessity and counterfactual semantics. Perhaps I will ultimately be forced to argue, on grounds similar to those adumbrated here, that the framework of possible worlds is too restrictive to be of use in these matters. In any case, I hope to explore these and related issues in depth elsewhere.
25. An earlier version of section II of this paper was read at a symposium on Ockham's Christology at the 1982 meetings of the Western Division of the American Philosophical Association. In writing and revising the paper I have benefited greatly from written comments provided by Marilyn McCord Adams, David Burrell, Philip Quinn, and the editor of this journal as well as an anonymous reader. Likewise, I have been aided immensely by conversations with Michael DePaul, Aron Edidin, Thomas Flint, Christopher Menzel, Alvin Plantinga, Howard Wettstein, and especially Thomas Morris.