Logic, Ontology and Ockham's Christology

New Scholasticism 57 (1983): 293-330

by Alfred J. Freddoso
University of Notre Dame

Let me begin somewhat perversely by making clear what I do not intend to do in this paper. I do not propose to offer a general defense of Ockham's resolution of the metaphysical perplexities engendered by the dogma of the Incarnation. In fact, I have argued elsewhere that his account of the hypostatic union is seriously deficient.1

Nor do I mean to refute the charge that Ockham's Christology is overtly or self-consciously Nestorian. This task has already been ably accomplished by Heiko Obermann and Marilyn Adams, who have shown that the Venerable Inceptor frequently affirms and nowhere denies that Christ is a single divine person who is truly man as well as truly God.2 He does, to be sure, join Scotus in ascribing to Christ's human nature a greater degree of metaphysical independence than does Aquinas, according to whom that nature lacks its own proper esse. Still, it does not follow that Ockham espouses some version of the 12th century "assumptus" Christology, according to which the Word of God assumed an independently existing human suppositum (and hence a man) but not, remarkably, a human person. This theory is indeed lightly camouflaged Nestorianism, and was exposed as such by Aquinas. Ockham, by contrast, draws the philosophically impeccable distinction between the heretical

    (1) This is possible: 'A man is assumed by the Word'

and its de re counterpart /294/

    (2) A man is possibly assumed by the Word,

which he, unlike Thomas, accepts as true. While the acceptance of (2) admittedly lends a Nestorian flavor to his Christology, the rejection of (1) just as surely preserves his orthodoxy.3

My purpose in this paper is, instead, to undermine the evidently widespread conviction--championed most vigorously in recent times by Peter Geach--that Ockham's characteristic positions in ontology and logic, viz., nominalism and the two-name theory of predication, render their proponents incapable of formulating a Christology that is at once both philosophically defensible and theologically orthodox. I will begin by arguing that Geach has not succeeded in showing that the two-name theory paves the way to Christological disaster. Section I examines a general argument for this contention, while section II focuses on the more specific charge that the two-name theory prevents Ockham from dealing adequately with problematic Christological propositions such as 'Christ as man began to exist'. I will then investigate the claim that it is Ockham's nominalism that subverts his Christology. Section III deals with his account of the signification of the abstract term 'humanity' and section IV with his nominal definition of the concrete term 'man '. While I will not pretend that Ockham's "official" doctrine concerning the terms 'humanity ' and 'man' can survive critical scrutiny unscathed, I will try to /295/ show that the weaknesses of that doctrine are not traceable to nominalism as such, and that a slightly modified version of Ockham's nominalism is theologically benign. Since Ockham's Christology has frequently been maligned and rejected simply because it is nominalistic, one corollary of my discussion will be that the real problem with his Christology has not been properly diagnosed.

A final word of introduction is required to situate this paper properly within its wider theological context. Though my proximate intention is to clear up some misunderstandings about Ockham's Christology, my ulterior motives are systematic rather than historical. Contemporary theologians rightly stress the importance of biblical studies for a fully developed Christology and concomitant theory of atonement. However, some have gone on to claim that the contemporary understanding of Scriptural depictions of Christ exposes as misguided or at least dispensable those traditional credal statements, conciliar pronouncements and theological ruminations that address the metaphysical questions quite naturally prompted by the fundamental Christian belief that God has become man for us and for our salvation.4 I will simply register without argument my deep disagreement with this claim. This is not to assert that a discussion /296/ of the pertinent metaphysical issues exhausts the mystery of the Incarnation or even that such a discussion can by itself constitute a complete systematic Christology. It is, however, to insist that a philosophically respectable treatment of those issues is an essential constituent of any plausible Christology. To ignore them or, as is also common today, to treat them in a manner regrettably innocent of philosophical sophistication is to give comfort to those who maintain that the dogma of the Incarnation is incoherent or self-contradictory.5 So despite the mainly historical pretensions of this paper, I hope that it will serve to illumine certain metaphysical problems in systematic Christology and perhaps even to suggest strategies for dealing with them.


Readers of Peter Geach's copious and distinguished works in logic and philosophical theology are familiar with his frequently voiced disapproval of the two-name theory of predication. According to this theory, an affirmative present-tense proposition such as 'Socrates is a man' is true just in case there is something which both the subject term and the predicate /297/ term name or, in technical terminology, supposit for.6 In the paper "Nominalism" Geach warns his clerical audience that the two-name theory has dire theological effects when presupposed in systematic treatments of the dogmas of the Trinity and the Incarnation.7 Ockham is afforded special attention precisely because he is a prominent theologian who unabashedly embraces this theory.

This is not the place to rehearse and assess Geach's many philosophical objections to the two-name theory. I will simply note in passing that I do not find those objections decisive. Some apply only to unsophisticated versions of the theory, and certainly not to Ockham's version. Others identify genuine disadvantages of the theory, but each of those disadvantages is, I believe, counterbalanced by a corresponding advantage that the two-name theory has over its Fregean competitor. In any case, what is at issue here is not the philosophical worth of the two-name theory, but rather the more serious question of whether, as Geach contends, that theory lures its unsuspecting adherents into Christological catastrophe. A general argument for this contention may, I believe, be extracted from the following passage, which occurs near the end of "Nominalism ":

    Aquinas explicitly rejects the two-name theory of predication and truth. Subject and predicate terms have different roles: a subject relates to a suppositum, a predicate to a form or nature, and the truth of an affirmative proposition consists in con-formity--the form that exists intentionally in the mind, signified by the predicate, answers to the /298/ form in the thing . .. Taking the subject-predicate distinction seriously gets him over the shoals on which two-name theorists like Ockham came to grief: e.g. he is readily able to distinguish pairs like 'Christ came to be a man' (true) and 'The man Christ came to be' (false) or 'Christ in so far as he is a man is a creature ' (true) and 'The man Christ is a creature' (false). For 'man' in subject position is a name--here, in apposition to the name 'Christ', it is a name of the eternal suppositum; 'man' in predicate position relates rather to the nature by which Christ is a man.8

There are actually two distinct arguments lurking here. The first makes essential use of the examples, and I will return to it in section II. The second is the more general argument that I am presently concerned with.

Ockham's nominalism consists in his rejection of common natures or forms such as those posited by Aquinas and Scotus. Given this rejection, he cannot subscribe to the realist's belief that concrete common terms in the category of substance (e.g., 'man') and their abstract counterparts (e.g., 'humanity') signify such natures. He maintains instead that these terms signify concrete individuals--in the case of 'man' and 'humanity' individual human beings. Now one suggestion at least intimated in the quoted passage is that the resulting nominalistic ontology is, because of its exclusion of common natures, too impoverished to permit a satisfactory solution to various puzzles generated by the dogma of the Incarnation. According to this suggestion, if 'man' functioning as a predicate term is thought to "relate to" supposita (ultimate subjects of characteristics) rather than to a common nature had by those supposita, then distinctions essential to the preservation of Christological orthodoxy simply cannot be made.

In sections III and IV I will examine in some detail the question of whether there can be an adequate nominalistic Christology. But the crucial issue here is this: exactly how does the above argument impugn the two-name theory of predication? /299/ Its main thrust seems to be that it is Ockham's nominalism, rather than his two-name theory, which is the real culprit.

Perhaps Geach is hinting that there is an intimate connection between the two-name theory and nominalism--a connection in virtue of which the sins of the latter may be justly imputed to the former. If so, what sort of connection could this be?

Nominalism does not presuppose or have as a necessary condition the two-name theory. One can consistently deny the reality of common natures as well as of more obtrusively Platonistic entities such as properties without embracing the two-name theory. Wilfrid Sellars is a prominent contemporary philosopher who combines his nominalism with a straightforwardly Fregean account of predication.

Perhaps Geach is insinuating that the two-name theory is more akin to a sufficient condition for nominalism. Perhaps he means to assert that once adopted, it makes nominalism enticing. So suppose that Ockham's first allegiance is to the two-name theory. Then we might be justified in understanding the general argument as follows:

"Nominalism is indeed the ultimate source of Ockham's Christological difficulties. The two-name theory is theologically odious precisely because it engenders nominalism. A two-name theorist is committed to the idea that predicate terms, like subject terms, play a naming role and, specifically, that they name individual supposita. This, in turn, leads naturally to an account of signification like Ockham's, according to which concrete terms and their abstract counterparts signify only individual supposita--and not common natures or forms. But such a theory of signification reflects an impoverished ontology that causes insuperable Christological problems."

If this is indeed Geach's argument, then it suffices to point out in rebuttal that neither he nor anyone else has established the central premise that the two-name theory naturally gives /300/ rise to a nominalistic account of signification. To the contrary, it seems clear that a two-name theorist might just as easily slide into the view that while predicates name or supposit for (and in this sense "relate to") individual supposita, it is nonetheless true that concrete terms in the category of substance signify (and in this sense "relate to") common natures instantiated by those supposita. For instance, he might claim that in the proposition 'Socrates is a man' the predicate term 'man' names or supposits for Socrates, but only because Socrates has or instantiates the common nature humanity which is signified by 'man'. In fact, Ockham assails this latter position in Summa Logicae II, chap. 2.9 So there is no reason to think that one who begins with the two-name theory of predication is more likely than not to adopt a nominalistic account of signification.

To return to Christology, many blame Ockham's nominalism--specifically, his nominalistic explication of the signification of the terms 'man' and 'humanity'--for his flirtation with Nestorianism. This is understandable, since if these terms signify human supposita (or persons) rather than a common nature had by each human person, then Christ's assuming a human nature seems tantamount to his assuming a human person. Geach seems to be making the additional claim that this nominalistic theory of signification has its origins in the two-name theory of predication. It is this connection that I have denied. Still, given that Ockham is indeed a nominalist, it remains an open question whether he can consistently and plausibly avoid Nestorianism. I will, as promised, return to this question below.


Perhaps, however, I have read too much into the passage quoted above. Perhaps Geach's intention there is simply to /301/ reiterate a more specific argument proffered earlier in "Nominalism." According to that argument the two-name theorist (presumably, whether he be a realist or a nominalist) cannot deal adequately with certain troublesome Christological propositions. Aquinas, as is well known pays special attention to Christological propositions containing reduplicative particles.10 Prima facie, it is crucial that a theologian be able to distinguish, say, the proposition 'The man Christ began to exist' (which is false) from the proposition 'Christ as man began to exist' (which is true on at least one of the readings deemed proper by Aquinas). But, says Geach:

    For a two-name theory no distinction like this can make sense. A term like 'man' or 'God' in subject or predicate position, is just a name and is the name of the same thing in either position. There can be no distinction between what is true of Christ as man and what is true of the man Christ.11

Two quite different criticisms can be gleaned from these remarks and those already cited above. The first is unimpressive, but the second will eventually lead us to an important philosophical lesson for the systematic theologian.

The first complaint is that the two-name theorist cannot consistently acknowledge the intuitively obvious distinction between a proposition of the form 'A, which is B, is C' and the corresponding proposition of the form 'A as B is C'. (I am assuming that 'The man Christ began to exist' is simply a variant of 'Christ, who is a man, began to exist'.)

This criticism is wholly gratuitous. One who adopts the two-name theory is not ipso facto constrained to deny that syncategorematic particles like 'as' affect the truth conditions of propositions in which they occur. In the case at hand, he will doubtlessly join Ockham in holding that a proposition of the /302/ form 'A as B is C' will, on any proper reading, be true only if A's being C depends in some way on its being B. On the other hand, he will surely maintain, again with Ockham, that a proposition of the form 'A, which is B, is C' is correctly expounded by the corresponding conjunctive proposition of the form ' A is B and A is C', which does not require for its truth that there be any non-trivial connection between A's being B and its being C. Hence, a two-name theorist can consistently hold that, say, 'Christ, who is a man, is a divine person' and 'Christ as man is a divine person' are distinct propositions differing in truth-value. It follows that he can indeed "make sense" of the distinction between what is true of Christ as man and what is true of the man Christ.

Nonetheless, Geach does stir some deep waters when he intimates that there are important specific instances in which Ockham cannot consistently assign the correct truth-values to Christological propositions of the forms in question. Take, for example, the indisputably distinct propositions 'The man Christ began to exist' and 'Christ as man began to exist'. The former is unproblematically false on Ockham's view, as it is on Aquinas'. But does Ockham agree with Aquinas that there is a proper reading on which 'Christ as man began to exist' is true? He does not.

Ockham's account of reduplication does, it should be noted, allow us to distinguish two different readings of this proposition: the reduplicative and the specificative.12 The main difference between them is that read reduplicatively, 'Christ as man began to exist' implies that necessarily, if anything is a man, it began to exist; whereas read specificatively, it does not imply this. Still, on both readings 'Christ as man began to exist' is true only if the corresponding unqualified proposition, 'Christ began to exist' is also true. And Ockham joins Aquinas in denying against the Arians and Psilanthropists that /303/ the Son of God, for whom the name 'Christ' supposits here, can be truly said without qualification to have begun to exist. So Ockham is forced by his own analysis of reduplicative propositions to count 'Christ as man began to exist' as false on any proper reading.

Should we conclude then, that Geach has succeeded in finding a devastating objection to Ockham's Christology--an objection that has as its rightful target the two-name theory of predication?

We should not conclude this. Geach's argument incriminates neither Ockham's Christology nor the two-name theory of predication. But to understand exactly why not, we must turn to what Aquinas has to say about the proposition 'Christ as man began to exist'.13

The reduplicative particle 'as' (in quantum or secundum quod), Thomas claims, has two senses, where the distinction he has in mind is different from the reduplicative/specificative distinction alluded to above. When 'as' is used in the first sense, then the term following it is made to stand for the suppositum named by the subject term. This reading renders the proposition false, since it then implies that the Son of God can, without qualification, be properly said to have begun to exist. At this point there is total agreement between Aquinas and Ockham, since the latter holds in effect that every reduplication, whether taken reduplicatively or specificatively, is made, in Thomas' terms, ratione suppositi.

However, Aquinas then goes beyond Ockham by claiming that on the most natural reading reduplications are made not ratione suppositi but rather ratione naturae. And "since by reason of the human nature, or with respect to the human nature, it belongs to Christ to be a creature," the proposition 'Christ as man began to exist' is true when the reduplication /304/ is taken in this way.14 It is absolutely crucial to note that when Thomas says "by reason of the human nature" he is speaking of Christ's individual human nature, i.e. that individual composed of a body and an intellective soul and united hypostatically to the Son of God. He is not, as he makes clear in several places, speaking of human nature in communi.15 In other words, he is reading the reduplication not only as made ratione naturae (rather than ratione suppositi) but also as bearing the specificative (rather than the reduplicative) sense. Hence, propositions such as 'Christ as man was born in Bethlehem' and 'Christ as man has the grace of union with a divine person' are no less true than 'Christ as man has an intellective soul'---even though this last proposition picks out a characteristic that Christ shares with every possible human being, while the first two do not.

Though this might at first not be apparent, Aquinas treatment of the proposition 'Christ as man began to exist' reveals the course by which he steers between the Christological counterpart of Scylla and Charybdis, viz. Nestorianism and Monophysitism.

How, we want to know, does Thomas understand reduplication made ratione naturae? Let a purely human characteristic of Christ be one which he has but would have lacked had he not become incarnate. What Aquinas means to suggest, I think, that Christ is the ultimate but mediate subject of his purely human characteristics. That is, such characteristics have as their immediate subject Christ's individual human nature and as their immediate but ultimate subject the divine person himself. Since they are ultimately the characteristics of the Son of God, the doctrine of the communication of attributes is, pace Nestorianism, upheld. The Son of God himself, and not just an independently existing man intimately related to him is truly said /305/ to be hungry, thirsty, moved by the death of his friend Lazarus, etc. On the other hand, since the purely human characteristics are only mediately the characteristics of the Son of God, Aquinas is able, pace Monophysitism, to preserve the doctrine that the divine and human natures remain integral and unmixed in Christ. The Son of God has the divine attributes necessarily, but he has his purely human characteristics only because he has freely assumed an individual human nature which alone serves as the immediate subject of those characteristics. When the reduplication in 'Christ as man began to exist' is made ratione naturae, then according to Thomas what is implicitly denied is that Christ's divine nature is the immediate subject of the characteristic of having begun to exist.

But why can we not infer from this qualified assertion the unqualified proposition 'Christ began to exist'? This question becomes even more perplexing when we notice that orthodoxy requires--and Thomas concurs--that unqualified propositions like 'Christ suffered', 'Christ died', etc.should be acknowledged as true. Isn't it embarrassingly arbitrary to treat these cases differently?

We might be aided here by the mereological model explicitly proposed in Thomas' commentary on the Sentences and at least adumbrated in both the Summa Theologiae and the disputed question De Unione Verbi Incarnati.16 (This model of the hypostatic union is also put forward in another source that I will reveal shortly.)

Some characteristics of an integral whole are predicated of it mediately in virtue of their being had immediately by proper parts of that whole. There are two types of cases to be considered. /306/ In the first type the characteristic in question may appropriately be predicated of the whole either with or without qualification. For instance, given that the facing surface of the apple before me is red, I may properly say either 'This apple is red with respect to its facing surface' or simply 'This apple is red'. Likewise, we may properly say either 'Christ died with respect to his human nature' or simply 'Christ died'. For on the cross Christ's human nature, "which is related to the composite person of Christ as a part,"17 came to be such that its soul no longer informed its body. By contrast, in the second type of mediate predication it is improper and misleading to omit the qualification. To use a standard medieval example, it is improper to say of a black man 'This man is white', even though the man's teeth are white. We must instead say 'This man is white with respect to his teeth' if we are to predicate whiteness of him appropriately. Similarly, because of heresies such as Arianism and Psilanthropism it is misleading and even wicked to assert without qualification 'Christ began to exist'. We should instead say, more cautiously, 'Christ began to exist with respect to his human nature' or, equivalently according to Aquinas, 'Christ as man began to exist'.

As these examples demonstrate, it is to some extent a matter of convention whether an unqualified proposition is permissible in a given case. One important question in the Christological cases, as in the more mundane mereological examples, is whether hearers are in general likely to be misled by an unqualified assertion. The emergence of new heresies or the revival of old ones will affect the answer. However, there is no danger of insurmountable confusion as long as the mereological model is kept vividly in mind, since it enables us to state precisely what we do and do not intend to affirm. /307/

Moreover, the mereological model has the additional virtue of enabling us to deflect at least temporarily the popular objection that the dogma of the Incarnation as traditionally formulated entails evident contradictions. Suppose that I have before me a sheet of paper that is blank on one side and has printing on the other. The terms 'having printing on it' and 'having no printing on it' are contraries if any are. Yet both can be truly predicated of the sheet of paper before me, the one with qualification and the other without. For I can truly assert both 'This sheet of paper has printing on it' and 'This sheet of paper has no printing on it with respect to one of its sides'. In the same way, the terms 'omniscient' and nonomniscient' are contraries if any are. Yet both 'Christ is omniscient' and 'Christ is nonomniscient with respect to his human nature' seem to be proper and orthodox. And they are not, at least not obviously, incompatible with one another. Of course, I am not claiming that no further elaboration is called for here. But I am maintaining that the mereological model furnishes the Christian apologist with an interesting first-stage response to what is often assumed to be a self-evidently invincible objection to orthodox belief, or at least one which the believer cannot even begin to answer without playing fast and loose with the concept of identity.

It is also worth reiterating that in many cases unqualified assertions relating to Christ's purely human characteristics are perfectly appropriate. In fact, to qualify needlessly smacks of Nestorianism, since it suggests that Christ's human nature is the ultimate as well as the immediate subject of those characteristics, where an ultimate subject of characteristics is, again, a suppositum or person.

To sum up, Aquinas uses the mereological model as an aid, albeit an imperfect one, in understanding the hypostatic union. And this strategy provides him with the resources to preserve /308/ the central elements of the Church's teaching about the Incarnation. Further--and it is important to see that this is a separate issue--he interprets what he calls "reduplication made ratione naturae" according to this model.

But what, someone is undoubtedly asking, has all of this to do with Ockham?

Given the apparent centrality of reduplication for Christology, it is mildly surprising that Ockham does not use a single Christological example in any of his discussions of reduplication in the Summa Logicae.18 What is genuinely shocking, however, is that he never once refers to the reduplicative construction in any of his discussions of the Incarnation!19

On the surface these facts corroborate Geach's contention that Ockham, as a two-name theorist, lacks the logical tools required for the construction of a plausible Christology. In fact, however, nothing could be further from the truth--which is, I believe, that on the issues now before us Ockham reaches essentially the same conclusions that Aquinas reaches, but by a rather different route. Moreover, the superficial differences between them have little to do with the two-name theory, but reflect instead an independent dispute about the logic of the reduplicative particle.

Let me explain. As we have seen, Ockham does not believe that there is a proper and literal reading on which the proposition 'Christ as man began to exist' is true. Nonetheless, it does not follow that he denies the truth which Aquinas believes to be enunciated (on one reading) by this proposition, viz. that Christ began to exist with respect to his human nature or, more simply, /309/ that Christ began to be a man'.20 Rather, what he implicitly denies in opposition to Thomas is that the reduplicative particle 'as' (in quantum or secundum quod) is equivalent to the preposition 'with respect to' (respectu or secundum or quantum ad). But it is precisely the latter which figures prominently in mereological contexts and is thus central to Thomas' explication of reduplication made ratione naturae. While Ockham repudiates the claim that there is such a thing as reduplication made ratione naturae, he apparently has no qualms about speaking of those characteristics which Christ has respectu naturae humanae, or secundum naturam humanam, or quantum ad naturam humanam.21

Most significantly, despite the fact that he does not mention reduplication in his discussions of the Incarnation, Ockham clearly embraces in his Reportatio the general Christological strategy ascribed above to Aquinas.22 There he draws the distinction between mediate and immediate predication and proposes the mereological model as an aid in discerning which propositions about Christ ought to be conceded and which ought to be denied. Like Aquinas, he claims that some unqualified propositions, e.g. 'Christ is a creature' ought to be denied because of their historical connection with one or another Christological heresy. Again like Aquinas, he suggests that whether a given unqualified proposition is to be conceded depends at least in part on how it is likely to be understood by the faithful.

So there is every reason to believe that Aquinas and Ockham are in substantial agreement on all of the deep Christological issues raised by the former's treatment of reduplicative propositions. They differ only on the secondary question of whether /310/ such propositions constitute an appropriate starting point for the discussion of those issues. To put it most simply, the one believes while the other does not that the proposition 'Christ as man began to exist' has a proper reading on which it is equivalent to 'Christ began to exist with respect to his human nature'. This difference, it should be emphasized, has no obvious connection with the two-name theory of predication. Moreover, contrary to what Geach claims, Ockham has no difficulty distinguishing what is true unqualifiedly of the man Christ from what is true of Christ with respect to his assumed nature. Nor is Ockham's nominalism relevant here, since the human nature which figures as a "part" in the mereological model of the hypostatic union is Christ's individual human nature rather than human nature in communi.

We may safely conclude, then, that Geach has failed to show that Ockham is led to the doorstep of Christological heresy by his adherence to the two-name theory of predication. But beyond this the present discussion suggests the somewhat surprising hypothesis that, received opinion to the contrary, the logic of reduplication is not central to Christology.

The most important feature of Aquinas' treatment of the proposition 'Christ as man began to exist' is his use of the mereological model of the hypostatic union. His claim that this model provides the resources for explicating a certain type of reduplication is a separate, logical thesis which is to all appearances theologically dispensable. One might easily side with Ockham in denying the equivalence between 'Christ as man began to exist' and 'Christ began to exist with respect to his human nature' and yet at the same time accept wholeheartedly Thomas' mereological account of the truth conditions of the latter.

In fact, there are good reasons for doing just that. First, we have many ordinary and uncontroversial cases in which a proposition of the form 'A is C with respect to B' is true while the /311/ corresponding unqualified proposition of the form 'A is C' is false. That is why this propositional form is significant for Christology. By contrast, it is at least initially plausible to believe that any proposition of the form 'A as B is C' implies the corresponding proposition of the form 'A is C'. Though Geach disparages this belief, infected as it is by "the nominalist principle about identity,"23 it is difficult to see what is gained by insisting that qualified Christological propositions are of the form 'A as B is C' when one is in any ease going to expound this form as 'A is C with respect to B'.

Second, the, mereological examples used by Aquinas and Ockham cannot easily be expressed by means of reduplicative propositions. While the proposition 'This man is white with respect to his teeth' is stilted, it is nonetheless well-formed, readily comprehensible and without a doubt possibly true. The same cannot be said for, say, 'This man as toothed (?) is white'. And I find that even the most promising candidate, viz. 'This man, in so far as he has teeth, is white' does not seem to me to be so much as possibly true.

Third, even if these considerations are not decisive, Aquinas' own discussion of reduplication betrays his belief that reduplication made ratione naturae is sui generis and can be explicated wholly independently of other types of reduplication. Hence, a theologian has no obvious need for a general theory of reduplication--at least as far as his Christology is concerned. In his paper "Omnipotence" Geach laments that "the logic of these propositions with 'as' in them is still an unsolved logical problem."24 What I am intimating here is that this unsolved logical problem need not impede contemporary Christology any more than it impeded medieval Christology.

Finally, an emphasis on reduplication carries with it the /312/ strong and dangerous temptation to treat the expressions 'Christ as man' and 'Christ as God' as ultimate logical subjects, corresponding to two distinct ultimate subjects of characteristics. As Geach himself warns, one who succumbs to this temptation puts himself "on a straight road to the Nestorian heresy."25 Geach avoids this pitfall by insisting that every reduplicative phrase is part of the predicate, rather than the subject, of the proposition in which it occurs. This appears to conflict with Aquinas' reasonable admission that at least some reduplications are made ratione suppositi. But even if Geach is correct, his point is a general one which, unlike Aquinas' mereological explication of reduplication made ratione naturae, yields no peculiarly Christological insights.

My own experience leads me to think that the more one reflects on the mereological model of the hypostatic union, the less inclined he will be to admit that the logic of reduplicative propositions is relevant to Christology. Perhaps such propositions are inescapable in systematic treatments of the Trinity, but in Christology time spent reflecting on reduplication appears to be time poorly spent indeed.

I have not attempted to develop the mereological model in any great depth here or to answer the many questions it occasions. However, enough has been said to warrant the modest conclusion that this model of the hypostatic union is both philosophically promising and consonant with the best traditional insights into the metaphysics of the Incarnation. As such, it deserves more attention from contemporary philosophical theologians than it has in fact received.


Even if the two-name theory has not been convicted of theological malfeasance, the charges against nominalism are still /313/ pending. These charges are, in fact, more weighty, if only because a longer tradition stands behind them.

Like every nominalist, Ockham is faced with the task of defusing the intuition that abstract terms signify and can be used to refer to abstract entities such as common natures. His method of coping with this problem is amply and, for our purposes, conveniently illustrated by what he says about the abstract term 'humanity'.26 He contends in effect that one who reasons correctly on philosophical grounds alone will reach the conclusion, which Ockham dubiously attributes to Aristotle, that 'humanity', like its concrete counterpart 'man', is a common term signifying individual human beings rather than a singular term signifying a nature common to all such individuals. Such a person will thus concede that every humanity is a man in just the same way that he acknowledges that every man is a man. Indeed, he will take 'man' and 'humanity' to be equivalent terms, necessarily signifying all and only the same concrete individuals. Thus the following argument will appear impeccable to him as long as he provisionally concedes the minor premise:

    (A) Every humanity is a man
           A humanity is assumed by the Son of God.
           Therefore, a man is assumed by the Son of God

Moreover, he will reject the realist's contention that even with respect to ordinary composite substances we can correctly distinguish the suppositum (ultimate subject of characteristics) from the common specific nature had by that suppositum. If he talks of natures at all, he will have in mind only individual composites of form and matter, and such composites will just be the individual substances in question rather than constituents had by those substances. Consequently he will regard the term '(individual) human nature' as equivalent to the term /314/ 'humanity', and he will find nothing objectionable about the following argument as long as he again concedes provisionally the minor premise:

    (B) Every individual human nature is a man
           An individual human nature is assumed by the Son of God.
           Therefore, a man is assumed by the Son of God

Unfortunately, however, we have here a case in which unaided reason, though operating correctly at every step, leads us to a belief that is heretical. For the conclusion common to (A) and (B) is tantamount to the Nestorian thesis that the Son of God united himself to a human suppositum or person.

To the chagrin of Geach and others, Ockham does not respond to this dilemma by dismantling completely the ontological theory which entails the major premises of (A) and (B). He believes, after all, that this theory represents the best that reason can attain without the aid of revelation. Instead, he replies that the theory holds for every possible case except one in which a divine person assumes a creaturely nature. It is only in such a case that a created individual nature is not itself a suppositum. Hence, what we learn from revelation is in effect that every humanity except Christ's is a human suppositurn and thus a man, and likewise that every individual human nature except Christ's is a human suppositum and thus a man. In addition, we learn that every man except Christ is just a humanity or individual human nature.

It follows that, pace Ockham's Aristotle, 'man' and 'humanity' (or: 'individual human nature') are not altogether equivalent in signification. 'Man', but not 'humanity', signifies the person of the Son of God; and 'humanity', but not 'man', signifies the individual human nature assumed and sustained by the Son of God. So every humanity is either a man or an individual human nature sustained by a suppositum distinct from itself; and every man is either an individual human nature not /315/ sustained by anything distinct from itself or a suppositum sustaining such a nature. Thus, at least, claims Ockham.

Is this response as implausible or arbitrary as Ockham's many and vociferous detractors have charged? To answer this question, we must carefully unravel the various strands of his resolution of the problems posed by (A) and (B). First, his response to argument (B), perhaps surprisingly, conforms exactly to that which emerges from Aquinas' own discussions of the Incarnation. For Aquinas concurs with Ockham in holding that every individual human nature, i.e. every individual composite of body and intellective soul, except Christ's, is a human suppositum and hence a man:

    .... those who denied that soul and body are united in Christ were motivated by the fear that they would otherwise be forced to posit a new person or hypostasis in Christ. For they saw that in merely human beings a person is constituted by the union of body and soul. However, in Christ the body and soul are united to one another in such a way that they are adjoined to something else more basic which subsists in the nature composed of them. And for this reason no new person or hypostasis is constituted by the union of body and soul in Christ. Instead, that composite of body and soul is adjoined to an already existing person or hypostasis.27

So Ockham's reply to argument (B) is implausible, arbitrary or otherwise deficient only if St.Thomas' is as well. I think that we may safely apply modus tollens here.

But what of Ockham's answer to argument (A)? What of his claim that every humanity except Christ's is a human suppositum and hence a man?

Ockham himself, of course, would contend that (A) and (B) are equivalent arguments, and hence that his rejoinder to (A) differs in no significant way from his rejoinder to (B). For, /316/ as we have seen, he holds that the term 'humanity' necessarily has the same signification as the common term 'individual human nature'.

But it is here, I believe, that his theory breaks down. There are, to be sure, philosophers besides Ockham who believe that the abstract term 'humanity' sometimes functions as a common term rather than as a singular term. They will insist, for example, that the humanity of Plato differs numerically from the humanity of Socrates, thus countering the opinion that 'humanity' designates a single abstract entity which, while remaining in itself one, is a constituent simultaneously of many distinct human beings. They typically argue that the humanity of Socrates is instead an individual constituent of Socrates, whether an "essence" (Aquinas) or an "aspect" (Wolterstorff) or a "form" (Geach),28 Some, like Geach, go on to deny that 'humanity' can ever be used properly outside of the context 'the humanity of _____', where the blank is filled in by a singular term referring to some individual human being. Others, like Wolterstorff, assert that when 'humanity' stands alone, it functions as a singular term designating an independently existing abstract entity which, though instanced by the individual humanities of Socrates, Plato and others, is not itself a constituent of any human being.

However, as far as I have been able to ascertain, Ockham stands alone in maintaining that 'humanity' is exclusively a common term signifying whole composites of body and intellective soul rather than proper constituents of such wholes. It is not astonishing that this claim has not attracted more support, given that it is both counterintuitive and strikingly implausible. As Aquinas points out, it offends the ear to hear such things as 'Socrates is humanity' or 'Humanity is Socrates'. And only /317/ unadulterated nominalist bravado could induce Ockham to swallow the idea that humanity is running when Socrates is running.

Nonetheless, it is important to see that Ockham's official account of the signification of 'humanity' is not mandatory for the nominalist as such. Perhaps a nominalist is well advised to resist the suggestion that 'humanity' signifies so much as individual constituents of ordinary human beings, since even this modest thesis is sufficient to give rise to a doctrine of common natures such as that favored by Aquinas. But nominalism as such surely does not require that 'humanity' signify whole individuals instead. Something more subtle is called for.

Ockham is not insensitive to the weakness of his position. Although his official view straightforwardly entails that the proposition 'Humanity is running' is possibly true, we find him in Sunma Logicae I, chap. 8 trying to accommodate the strong intuition that this proposition is necessarily false.29 Paradoxical as this attempt is, however, it issues in an alternative and, as Michael Loux has argued, revolutionary nominalist strategy for handling abstract terms.30

According to Ockham's official theory, the terms 'humanity' and 'individual human nature' are common terms which are necessarily equivalent in signification. By contrast, the alternative suggestion is that just as we might adopt the convention of using the letter 'A' to stand for the longer expression 'Every man ......', so too our language already incorporates a similar convention according to which the singular term 'humanity' serves as a convenient abbreviation for one or another lengthier propositional context such as 'A man qua man ......' or 'A man necessarily ......' or 'Necessarily, if anyone is a man, then he ......'. But if this is so, then it is, strictly speaking, /318/ a mistake to ask directly about the semantic characteristics of the term 'humanity', just as it is inappropriate to inquire about the semantic characteristics of 'A' given the convention noted above. In the latter case semantic questions become fitting only after we have transformed, say, 'A is running' into 'Every man is running', thus eliminating 'A' in favor of its more cumbersome, but also more perspicuous, counterpart. So too, Ockham intimates, we should postpone a semantic investigation of propositions in which 'humanity' occurs until after those propositions have undergone the relevant transformations into more perspicuous form.

This strategy, if successful, solves the problem of abstract terms by demonstrating that such terms are eliminable from our language without loss of expressive power. Moreover, it is not vulnerable to the objections that plague Ockham's official view, since on any of the substitutions for 'humanity' proposed above, propositions such as 'Humanity is Socrates' and 'Humanity is running' turn out to be necessarily false. Again, on this alternative account abstract terms are unproblematically singular--and so the major premise of argument (A) can be rejected as ill-formed. (This response to (A) conforms, of course, to what St. Thomas himself would say).

Fortunately, my aims in this paper do not dictate that I offer a detailed defense of this alternative account of abstract signification. I need only point out that such an account is philosophically respectable and, unlike Ockham's official account, not wildly counterintuitive. The attempt to eliminate abstract terms has, in fact, become a classic nominalist ploy, most relentlessly pursued in recent analytic philosophy by the likes of Sellars and Quine.

Finally, it is important. to see that this alternative account creates no problems in Christology. According to faith, Christ assumed and is now united to a human nature. But, as I have stressed repeatedly, we are speaking here of a concrete individual /319/ human nature rather than of human nature in communi. The dogma of the Incarnation does not by itself require that the abstract term 'humanity' signify a Platonic property or even a Thomistic or Scotistic common nature. Moreover, a nominalist who adopts the alternative account can still consistently affirm with Aquinas, Scotus and Ockham that in every instance save one the union of a body with an intellective soul has produced a human suppositum or person. So a nominalistic account of abstract signification does not by itself constitute a barrier to Christological orthodoxy.

In fact, if there is any genuinely formidable theological problem with Ockham's reply to argument (A), it has to do not with his Christology but rather with his conception of the relation between faith and reason. As we saw above, he attributes to Aristotle a position which he deems to be heretical and yet far superior to its competitors on philosophical grounds alone. In fact, he seems willing to admit that Aristotle's (putative) argument for the conclusion that every humanity is a man meets all the conditions (validity, self-evident nature of premises, etc.) necessary for its being a demonstration in the strict sense. Compare this with the following famous chain of reasoning: Aristotle claims to have demonstrated that the world is eternal; but this proposition is heretical; hence, there is a philosophical error in Aristotle's argument--an error, that is, which can at least in principle be diagnosed without any appeal to divine revelation. In contrast, on Ockham's view the mere (alleged) fact that Aristotle claimed to have demonstrated that every humanity is a man is not sufficient grounds for thinking that he committed a philosophical error.

The issues involved here are admittedly complex, and I do not pretend to have either a comprehensive epistemological theory or an adequate understanding of the relation between faith and reason. Still, anyone who feels that Christian belief is epistemically respectable will not find it difficult to appreciate /320/ Geach's uneasiness about Ockham's view of the matter.31 But even granting Geach this much, we have as yet found no evidence that either Ockham's nominalism or his conception of the relation between faith and reason causes irreparable damage to his Christology.


Geach offers one final argument in his effort to incriminate Ockham's nominalism. Even though this argument will help us unmask what I believe to be the fatal flaw in Ockham's Christology, I will try to show that, despite appearances to the contrary, this flaw does not find its origins in his nominalism.

As we have seen, Ockham proposes a theory of signification according to which the concrete term 'man' signifies individual human beings rather than a nature common to such individuals. In several places he goes on to claim that the dogma of the Incarnation compels us to acknowledge that 'man' has a disjunctive nominal definition, viz, 'either a nature composed of a body and an intellective soul and not sustained by another, or a suppositum sustaining such a nature'.32 The first disjunct applies to every man except Christ, the second disjunct to Christ alone.

At this point Ockham's nominalism appears to have put him at a distinct disadvantage, since it keeps him from appealing to common natures when he sets out to formulate a definition of 'man' that is univocally applicable to Christ and other human beings. Apparently, what he needs, but as a nominalist cannot have, is the realist's handy distinction between a suppositum and the common human nature that it possesses. For whether a given suppositum is a divine person or a human person, it will be a man simply in virtue of its having human nature /321/ in communi. And such a nature will be unproblematically definable in such a way that its definition is univocally true of all human beings, including Christ. Ockham, on the other hand, seems driven by his nominalism to the desperate expedient of resorting to a disjunctive definition. Nor is Geach slow to seize upon this note of seeming desperation:

    And though (Ockham) can claim that his definition of 'homo' makes it unequivocally true of Christ and other men, this is a mere subterfuge; for Christ is not verus homo as we are, if 'homo' applies to him and us only because one half of the disjunctive definition applies to him and the other half to us. Moreover, this definition of 'homo' would certainly not have been in the mind of any Latin-speaking contemporary of Christ's; so on Ockham's showing Pilate will have erred in saying 'Ecce Homo', since what Pilate meant by 'homo' will not on Ockham's showing have been true of Christ.33

A defender of Ockham might initially be inclined to reply that it is by no means startling that we should discover something unexpected about the meaning of the term 'man' when we submit the dogma of the Incarnation to rational scrutiny. Christ is truly human but, unsurprisingly, he differs from other human beings in some important ways, one of which is captured by the disjunctive nominal definition of 'man'.

This response, however fails for a reason very similar to that articulated by Geach at the end of the quoted passage. Ockham recognizes two different types of synonymy, which for present purposes I will dub 'weak' and 'strong' . Two categorematic terms or expressions are synonymous in the weak sense just in case necessarily, they signify all and only the same individual things. For instance according to Ockham the terms 'God' (Deus) and 'the divine nature' (deitas) are weakly synonymous, even though a speaker unacquainted with the doctrine of divine simplicity might understand both terms without believing that they are equivalent in signification. Likewise, /322/ according to Ockham's Aristotle, the terms 'man' and 'humanity' are synonymous, but only in the weak sense. This is why the claim that they are synonymous cannot be assumed to be self-evident, but must instead be supported by arguments.

By contrast two categorematic terms or expressions are synonymous in the strong sense only if necessarily, whoever understands both of them believes them to apply to all and only the same things. Now Ockham pretty clearly holds that a term and its nominal definition are synonymous in the strong sense. This is true, for instance, of the term 'white (thing)' and its nominal definition 'something having whiteness'. It follows that the disjunctive formula under discussion is the nominal definition of the term 'man' only if it is impossible that someone should grasp both of them without believing them to apply to all and only the same things. But Geach is clearly correct in suggesting that this is not impossible. So the proposed response to Geach's argument is one which Ockham cannot consistently endorse.

Again, one might easily be led to believe that this problem stems directly from Ockham's nominalism. The realist, after all, claims that the common nature shared by Christ and other human beings can be expressed straightforwardly by a non-disjunctive definition such as 'rational animal' or 'individual (suppositum) having a body and an intellective soul'. But the nominalist spurns any appeal to common natures. Therefore, the argument goes, he finds it impossible to formulate a simple, non-disjunctive definition of 'man'.

Attractive as it seems, this line of reasoning is spurious. The truth is that Ockham's problems can be traced not to his nominalism, but to a purely theological assumption which he shares with as fervent an anti-nominalist as Duns Scotus. In the remainder of the paper I will attempt to demonstrate this claim.

To begin, it is rather astonishing that Ockham even speaks of the "nominal definition" of the term 'man'. For he often /323/ uses 'man' as a paradigmatic example of an absolute term, and according to Summa Logicae I, chapter 10 absolute terms do not, properly speaking, have nominal definitions!34 Only connotative terms do.

Exploring the reasons for this thesis about absolute terms would take us deep into the largely uncharted jungles of Ockham's distinction between absolute and connotative terms.35 For the present it is sufficient to note that this distinction has rather controversial metaphysical underpinnings. To put it succinctly, absolute terms have real (rather than nominal) definitions because they signify things in a metaphysically basic and privileged way, whereas connotative terms are non-basic and in theory eliminable in favor of formulas (nominal definitions) whose only categorematic terms are absolute. The implicit assumption is that we could in principle give an ontologically adequate description of the world without using any connotative terms.

According to Ockham an absolute term admits of two types of real definition: metaphysical and natural. A metaphysical definition is stated in terms of genus and difference, while a natural definition makes reference to the essential parts (matter and form) of the things signified by the term being defined. Moreover, real definitions are, unlike nominal definitions, only weakly synonymous with their definienda. So, for instance, the metaphysical definition 'rational animal' and the natural definition 'individual having a body and an intellective soul' are weakly synonymous with the term 'man'.

Given this background, we are in a position to see that nominalism is not the source of Ockham's difficulties with the term 'man'. First of all, since a nominalist need not abandon /324/ the theory of real definition, he can claim with equanimity that the two real definitions of 'man' apply univocally to all human beings, including Christ. He will, of course, argue--as Ockham in fact does--that the use of real definitions does not carry with it a commitment to the reality of common natures. But the relevant arguments are at least impressive enough to render moot the assumption that such a commitment is obvious or even self-evident.

Second, a Christian nominalist can quite consistently accept the following biconditional with a disjunctive right-hand side:

    (3) Necessarily, for any x, x is a man if and only if x is either (a) an individual nature composed of a body and an intellective soul and not sustained by anything distinct from itself, or (b) a suppositum sustaining an individual nature composed of a body and an intellective soul.

Like Aquinas and other realists who embrace (3), he can take (3) to be a non-definitional truth which does not yield a strong synonym for the term 'man'. Hence, someone might understand both the term 'man' and the right-hand side of (3) and yet reject (3). Moreover, as noted in section III, anyone--nominalist or realist--who accepts (3) on theological grounds will join Ockham and Aquinas in denying the first premise of argument (B), insisting instead that every individual human nature except Christ's is a man.

A nominalist, then can consistently take 'man' to be an absolute term having two real definitions, each of which is univocally applicable to Christ and other human beings. In addition, he can consistently take (3) to be a non-definitional metaphysical truth, thereby escaping the clutches of argument (B) . The resulting metaphysical account of the hypostatic union will be no less plausible or orthodox than Aquinas' own account--at least as far as the issues which we have been discussing are concerned. Why, then, does Ockham reverse himself in Summa Logicae III-4, /325/ chapter 10 by claiming that in light of the mystery of the Incarnation, the Christian theologian must part company with the mere philosopher and treat 'man' as a connotative term? Why does he, implausibly, convert (3) into a "nominal definition" of 'man'? Here is his own explanation:

    . . even though philosophers regard the name 'man' as a purely absolute name which in the nominative case does not signify any one of its significata more than another, theologians do not regard it as purely absolute in this sense. For if it were purely absolute in this sense, then it would be equivalent to 'humanity'. And if that were so, then 'The Son of God is a man' would have to be denied in the same way that 'The Son of God is a humanity' has to be denied. But this is not the case. So according to theologians the name 'man' connotes or consignifies, at least potentially, a divine suppositum which, even if it were not a man, would still be able to be a man. From this it follows that I have been speaking in accord with the usage of philosophers in many of the examples I have given involving the name 'man'.36

Given our previous discussion, I will take the liberty of understanding 'individual human nature' where Ockham uses 'humanity' in this passage. Even so, however, his argument is a baffling one. One would antecedently expect Ockham to affirm that 'man' signifies equally each human being, i.e. each suppositum which is a human being, be it a divine person or a human person. For his official view is that a categorematic term signifies primarily (rather than connotes or consignifies) each thing for which it can supposit in a simple present-tense proposition.37 And because of the Incarnation the term 'man' in fact supposits for the Son of God in such propositions. Why, then, does Ockham claim that the term 'man' merely "consignifies" the Son of God?

Moreover, it is far from evident that if 'man' were an absolute /326/ term, then it would have to be equivalent to 'individual human nature'. On the contrary, it seems just as plausible to hold that both terms are absolute even though they are not equivalent--or even to hold that 'individual human nature' is a connotative term, having 'either a man or something sustained by a man' as its nominal definition. Why does Ockham insist otherwise?

Perhaps the context of the quoted remarks can shed some light on these puzzles. The above passage occurs within a discussion of fallacies of a figure of speech. Ockham has just offered an explanation for why the material inference

    (C) A man ceases (begins) to be a man; therefore a man ceases (begins) to exist

is, according to philosophers, valid, while the similar inference

    (D) A white thing ceases (begins) to be white; therefore a white thing ceases ( begins ) to exist

is invalid. I believe that the following reconstruction faithfully reflects the line of reasoning which takes Ockham from the discussion of (C) and (D) to the argument we have been considering:38

"'Man' is, according to philosophical usage, an absolute term, since it is a simple term in the category of substance. 'White (thing)', on the other hand, is a connotative term in the category of quality that differs in signification from its abstract counterpart, the absolute term 'whiteness'. The fact that 'man' is absolute while 'white' is not suffices to explain the apparent disparity between (C) and (D) . (Notice that the substitution of 'a whiteness' for 'a white thing' and 'white' in (D) produces a valid inference.) Interestingly, however, a /327/ theologian cannot admit that (C) is valid. For faith teaches us that Christ is a man who begins to be a man without beginning to exist and who could (so Ockham thinks) cease to be a man without ceasing to exist. But since he denies that (C) is valid, the theologian must be treating 'man' as a connotative term. On the other hand, if we substitute 'individual human nature' for 'man' in (C), then the resulting inference is one which even the theologian can acknowledge as valid. So he must be taking 'individual human nature' to be an absolute term."

This chain of reasoning is extremely illuminating, since it suggests that on Ockham's view a term is absolute only if it is, in modern parlance, a rigid designator of whatever it signifies. Let us say, departing somewhat from Ockham's own usage, that a thing x is essentially F just in case x is in fact F and cannot exist without being F. Ockham seems to hold that a term 'T' is absolute only if necessarily, whatever is T is essentially T. Hence, 'man' is absolute only if necessarily, whatever is a man is essentially a man. Since the Son of God is a man who could and, in fact, did exist without being a man, he is not essentially a man in the sense in question.39 It follows that 'man' is not an absolute term.

I will not pause to consider the devastating effect this account of absolute terms would have had on Ockham's logic and ontology if he had applied it consistently throughout his philosophical works. Suffice it to say that if 'man' is not an absolute term, then for precisely the same reason none of the genera under which it falls ('animal', 'body', etc.) is absolute. Indeed, if Ockham is correct in asserting that any created nature could be assumed by a divine person, then none of the concrete terms /328/ which Aristotle assigned to the category of substance is absolute.

Actually, however, a simple resolution of this difficulty is readily available. An extensionally equivalent division of absolute from connotative terms results if we discard the necessary condition formulated above and replace it with the weaker condition that a term 'T' is absolute only if possibly, something which is T is essentially T. If we adopt this condition, we can preserve the claim that 'man' is an absolute term as long as we accept the eminently plausible

    (4) Possibly, some man is essentially a man.

Further, we can reasonably attribute the invalidity of (C) to the fact that there is at least one man who is not essentially a man. Since (C) is not in anyone's eyes a formally valid inference, such a move will not constitute an undue intrusion of theology into logic. Finally, we can add that while (C) is invalid, its close relative

    (E) A man who is not a divine person ceases (begins) to be a man; therefore a man ceases (begins) to exist

is valid. For every man other than a divine person is such that his ceasing to be (coming to be) a man entails his ceasing to be (coming to be) simpliciter.

Each of these claims is, of course, consistent with nominalism. Further, even a theologian who is a realist will be likely to count (C) as invalid, (E) as valid and (4) as true. So if Ockham were to adopt the strategy just outlined, he could enhance the plausibility of his Christology while at the same time preserving his nominalistic positions in logic and ontology.

Sadly, however, he demurs at this point. Astoundingly, he rejects both (4) and the claim that (E) is valid. And here we come face to face for the first time with the real disease infecting Ockham's Christology: he concurs with Scotus in accepting on purely theological grounds the extraordinary thesis that /329/ every individual human nature is both possibly such that it is a man and possibly such that it is united to a divine person (and hence not a man). More precisely, he embraces

    (5) Necessarily, each individual human nature n is such that for any moment t, both

      (a) if n is a man at t, then God has the power to bring it about that n is united to a divine person (and is hence no longer a man ) at some moment later than t; and
      (b) if n is united to a divine person at t, then God has the power to bring it about that n is not united to a divine person (and hence is a man) at some time later than t.

So according to Ockham any individual human nature which is in fact a man might cease to be a man without ceasing to exist, and any individual human nature which is in fact not a man might begin to be a man without its being the case that any new thing comes into existence.

Ockham apparently feels that a Christology which, like Aquinas', rejects (5) does not ascribe sufficient metaphysical independence to Christ's human nature and thus leans too heavily toward Monophysitism or even Docetism. By contrast, the proponent of (5) allows for the possibility that Christ's human nature might go on existing, now as a created human person, were Christ to "lay it down". Moreover, the acceptance of (5) ensures that Christ's human nature is exactly like every other in that each such nature is assumable by a divine person.

It is easy to see that (5) is incompatible with (4), and that someone who accepts (5) will claim that 'man' is not an absolute term even on the alternative account proposed above. It is also easy to see why anyone who embraces (5) must hold that (E) as well as (C) is invalid. If (5) is true, then an individual human nature which is not united to a divine person might cease to be a man without ceasing to exist. It might go on existing while being sustained by a divine suppositum. I have argued at length elsewhere that (5) destroys the credibility, if not the orthodoxy, of any Christology which incorporates /330/ it. Here I have tried to establish only the more modest thesis that Ockham's nominalism is in no way to blame for his contention that 'man' is a connotative term with a disjunctive nominal definition. The responsibility for that claim clearly accrues to his acceptance of (5), and he accepts (5) on purely theological grounds.

In conclusion, there is no good reason for believing that either Ockham's nominalism or his two-name theory of predication leads him to the brink of Christological disaster. Perhaps, as Geach argues, one or the other of these philosophical positions creates insoluble problems for a systematic explication of the dogma of the Trinity. But that is a topic for another occasion.40


1. See my "Human Nature, Potency and the Incarnation," Faith and Philosophy 3 (1986): 27-53. 

2. Heiko Obermann, The Harvest of Medieval Theology (Cambridge, MA, 1963), pp. 249-261; and Marilyn McCord Adams, "Relations, Inherence and Subsistence: or, Was Ockham a Nestorian in Christology?", Nous 16 (1982 ), 62-75.

3. Ockham's rationale for accepting (2) will become clearer in section IV. To anticipate, he believes that a given individual nature composed of body and intellective soul might first be a man and then be assumed by a divine person. (1) is false, since once the nature is assumed, it ceases to be a man--just as a white thing which becomes black ceases to be white. Still, (2) is true, since something which is now a man (viz. this individual human nature) might at some future time be assumed--just as 'This white thing is possibly black' is true because this thing which is now white might at some future time become black. Ockham sees the two cases as perfectly analogous. See his Quodlibeta Septem IV, 7 in Joseph Wey, ed., Ockham: Opera Theologica (hereafter: OT) (St. Bonaventure, NY, 1980), vol. 9, pp. 328-337.

4.This claim is rarely stated as baldly as I have put it here. More often it emerges only gradually from the mist of qualifications in which the obligatory paean to tradition is enshrouded. Curiously, the qualifications vary from author to author and even conflict with one another. Some feel that the formulas of Chalcedon and medieval theology were proper within their limited historical milieus, while others deem them absolutely improper or at least unfortunate. Again, some contend that metaphysical speculation of any kind invariably distorts the meaning of the Incarnation, while others object only to "outmoded" Aristotelian-medieval concepts. (Though modern man can no longer comprehend the notions of person and nature, he apparently has little difficulty grasping their more lucid Heideggerian or Whiteheadian successors.) For popular and rather sympathetic accounts of these and other trends in contemporary Catholic Christology, see Gerald O'Collins, What Are They Saying About Jesus? (New York, 1977) and Richard McBrien, Catholicism: Study Edition (Minneapolis, 1981), esp. pp. 369-546.

5. This objection to the dogma of the Incarnation has in recent times gained acceptance even among theologians working within the Christian tradition. Thus John Hick. "... orthodoxy insisted upon the two natures, human and divine, coinhering in the one historical Jesus Christ. But orthodoxy has never been able to give this idea any content. It remains a form of words without an assignable meaning. For to say, without explanation, that the historical Jesus of Nazareth was also God is as devoid of meaning as to say that this circle drawn on paper is also a square. Such a locution has to be given semantic content: and in the case of the language of incarnation every content thus far suggested has had to be repudiated. The Chalcedonian formula, in which the attempt rested, merely reiterated that Jesus was both God and man, but made no attempt to interpret the formula. It therefore seems reasonable to conclude that the real point and value of the incarnational doctrine is not indicative but expressive, not to assert a metaphysical fact but to express a valuation and evoke an attitude." From "Jesus and the World Religions," in John Hick, ed., The Myth of God Incarnate (Philadelphia, 1977), p. 178.

6 For a brief account of Ockham's understanding of the notion of supposition, see pp. 1-16 of my "Ockham's Theory of Truth Conditions," in Alfred J. Freddoso and Henry Schuurman, trans., Ockham's Theory of Propositions: Part II of the Summa Logicae (hereafter: OTP ) (Notre Dame, IN, 1980). Throughout I will follow Ockham and Geach in using the term 'proposition' to refer to sentences, whether spoken, written or mental.

7. "Nominalism," in Peter Geach, Logic Matters (Berkeley, 1972), pp. 289-301.

8. "Nominalism," p. 300.

9. Summa Logicae (hereafter: SL) II, chap. 2, in P. Boehner, G. Gal and S. Brown, eds, Ockham: Opera Philosophica (hereafter: OP), vol. 1 (St. Bonaventure, NY, 1974), pp. 249-254. (Translated in OTP, pp. 86-91).

10. See esp. Summa Theologiae (hereafter: ST) III, 16, 9-12.

11. "Nominalism," p. 295.

12. SL II, chap. 16 (OP, vol. 1, p. 295). (Translated in OTP, pp. 130-131).

13. See ST III, 16,10.

14. ST III, 16, 10, responsio.

15. See, eg, ST III, 4, 5, responsio; 16, 8 ad 4; 16, 9 ad 3; 16, 11 ad 1; and 16, 12, responsio.

16. In Quatuor Libros Sententiarum III, 11, 1, 3; ST, III, 16, 8, responsio and 16, 2, ad 2; De Unioni Verbi Incarnati, unica, 2 ad 2 and unica, 3, responsio. Thomas, of course, is quick to point out that all models of the hypostatic union are deficient. In particular, the mereological model does not represent adequately the fact that Christ's human nature is related to him "essentially" and is not merely an appendage, so to speak.

17. In Quatuor Libros Sententiarum III, 11, 1, 3, responsio. St. Thomas adds here: quamvis proprie pars dici non possit, nec proprie persona composita. Cf. fn. 16, above.

18. See, e.g., SL II, chap. 16 (OP, vol. 1, pp. 289-296); SL III-1, chap. 65 (OP, vol. 1, pp. 497-500); SL III-3, chap. 6 (OP, vol. 1, pp. 603-604); and SL IV, chap. 11 (OP, vol. 1, pp. 818-819).

19. See, e.g., Reportatio III, 1 and 10, in F. Kelly and G. Etzkorn, eds., OT, vol. VI (St. Bonaventure, NY, 1982), pp. 3-42 and 315-350; and Quodlibeta Septem IV, 7 and 8, and V, 10 and 11 (OT, vol. 9, pp. 328-341 and 518-528).

20. For example, in SL II, chap. 19 (OP, vol. 1, p. 315) Ockham assumes that 'The Son of God began to be a man' is true in discussing the reason for the invalidity of the following inference: 'The Son of God began to be a man; therefore the Son of God began to be something'.

21. See, e.g., Reportatio III, 1 (OT, vol. 6, pp. 7-8).

22. Reportatio III, 10 ( OT, vol. 6, pp. 323-324).

23. "Nominalism," p. 301.

24. "Omnipotence," in Peter Coach, Providence and Evil (Cambridge, 1977), p. 27.

25. "Omnipotence," p. 26.

26. My discussion here will be based primarily on SL I, chaps. 7 and 8 (OP, vol. 1, pp. 23-34), and Quodlibeta Septem V, 10 and 11 (OT, vol. 9, pp. 518-528) .

27. ST III, 2, 5 ad 1. Notice that although the medieval discussions presuppose a hylomorphic account of human nature, the doctrine of the Incarnation itself requires only that Christ's human nature is, metaphysically speaking, like every other in its composition. In this paper I am simply assuming that some version of the hylomorphic theory is correct.

28. See Aquinas, De Ente et Essentia, chap. 2; Nicholas Wolterstorff, On Universals (Chicago, 1972), pp. 128-149; and Peter Geach and Elizabeth Anscombe, Three Philosophers (Ithaca, NY, 1961 ), pp. 77-80.

29. OP, vol. 1, pp. 29-30.

30. See "'The Ontology of William of Ockham," pp. 1-22 in Michael J. Loux, trans, Ockham's Theory of Terms: Part I of the Summa Logicae (Notre Dame, IN, 1974)

31. "Nominalism," pp. 297-299.

32. See, e.g., SL I, chap. 7 (OP, vol. 1, p. 25); and Quodlibeta Septem V, 10 (OT, vol. 9, p. 520).

33. "Nominalism," p. 297.

34. OP, vol. 1, p. 35.

35.  For a good treatment of the issues involved here, see Paul V. Spade, "Ockham's Distinctions between Absolute and Connotative Terms," Vivarium 13 (1975), 55-76.

36. OP, vol. 1, p. 811.

37. SL I, chap. 33 (OP, vol. 1, p. 95). More exactly, a term signifies primarily whatever it supposits for personally in a simple present-tense proposition. See OTP, pp. 1-16

38. The following reconstruction is based on what Ockham says just before the passage quoted above. See OP, vol. 1, pp. 810-811. Note that according to Ockham,'whiteness' is a common term signifying individual qualities, viz. whitenesses.

39. There are, of course, other senses of the word 'essential'. For instance. Aquinas claims that the hypostatic union is an 'essential' rather than an 'accidental' union in order to disengage heresies according to which Christ merely appeared in human form or is related to his human nature merely in the way someone is related to the clothes he wears.

40. An earlier version of section II of this paper was delivered at a symposium on Ockham's Christology at the 1982 meetings of the Western Division of the American Philosophical Association. The principal paper at that symposium was the one by Marilyn Adams alluded to in note 2 above. I wish to thank Professor Adams for providing me with an occasion to reflect philosophically on the mystery of the Incarnation.