William Lane Craig is Research Professor of Philosophy at Talbot School of Theology in La Mirada, California. He lives in Atlanta, Georgia, with his wife Jan and their two teenage children Charity and John. At the age of sixteen as a junior in high school, he first heard the message of the Christian gospel and yielded his life to Christ. Dr. Craig pursued his undergraduate studies at Wheaton College (B.A. 1971) and graduate studies at Trinity Evangelical Divinity School (M.A. 1974; M.A. 1975), the University of Birmingham (England) (Ph.D. 1977), and the University of Munich (Germany) (D.Theol. 1984). From 1980-86 he taught Philosophy of Religion at Trinity, during which time he and Jan started their family. In 1987 they moved to Brussels, Belgium, where Dr. Craig pursued research at the University of Louvain until 1994.
In a provocative and carefully argued paper, Michael Rea and Jeffrey Brower (hereafter R-B) have offered a creative, new way of understanding the Trinity based on the analogy of hylomorphic composition as understood by Aristotle. They present their solution as “the most philosophically promising and theologically satisfying solution currently on offer.”
R-B formulate the problem of the Trinity in terms of the seeming incompatibility of the three theses:
(T1) Each person of the Trinity is distinct from each of the others.
(T2) Each person of the Trinity is God.
(T3) There is exactly one God.
These three theses appear to imply that three distinct beings are each identical with one being, which is incoherent.
Like the Social Trinitarian and the Relative Identity theorist, R-B avert incoherence by denying that (T2) is a statement of absolute identity. They reject, however, the usual Social Trinitarian and Relative Identity interpretations of (T2) in favor of an interpretation inspired by an Aristotelian account of material constitution. In their view (T2) should be understood in terms of numerical sameness without identity.
The relation of numerical sameness without identity features prominently in Aristotle’s treatment of material constitution. Aristotle believed in a wide range of hylomorphic compounds, objects constituted by matter plus some organizing form. R-B explain that he even accepted the reality of strange objects like “seated Socrates,” which temporarily exists while Socrates is sitting down and is composed of a thing which is a substance in its own right (Socrates) plus some accidental form (seatedness). Although R-B acknowledge the kookiness of objects like seated Socrates, they insist that fans of common sense do:
believe in many things relevantly like seated Socrates. That is, we believe in things that can very plausibly be characterized as hylomorphic compounds whose matter is a familiar material object and whose form is an accidental property. We believe in fists and hands, bronze statues and lumps of bronze, gold coins and lumps of gold, cats and heaps of cat tissue, and so on.
In each case, the first member of the pair is composed of the second member of the pair, which is taken to be an object in its own right, plus some accidental form. But such a belief gives rise to the problem of material constitution. For a fist is not the same thing as a hand (a fist is essentially clenched whereas a hand is not), and yet when the hand takes the shape of a fist, there are not two material objects present but only one. R-B explain that for Aristotle the hand and the fist are distinct in being but one in number, that is to say, although the hand and the fist are distinct entities, they are only one material object. When the hand is clenched, the hand and the fist are numerically the same without being identical. R-B acknowledge that it is hard to swallow the idea that numerical sameness need not involve identity, but they dismiss such mental reservations, observing that any solution to the problem of material constitution is going to be counterintuitive.
Assuming the acceptability of the Aristotelian solution to the problem of material constitution, R-B explain its relevance to the doctrine of the Trinity:
. . . the Persons of the Trinity can also be conceived of in terms of hylomorphic compounds. Thus, we can think of the divine essence as playing the role of matter, and we can regard the properties being a Father, being a Son, and being a Spirit as distinct forms instantiated by the divine essence, each giving rise to a distinct Person. As with matter, we regard the divine essence not as an individual thing in its own right but rather as that which, together with the requisite ‘form’ constitutes a Person. Each person will then be a compound structure whose matter is the divine essence and whose form is one of the three distinctive Trinitarian properties. On this way of thinking, the Persons of the Trinity are directly analogous to particulars that stand in the familiar relation of material constitution.
R-B proceed to note three disanalogies between the case of the Trinity and cases of familiar material constitution:
1. In the case of the Trinity, unlike the case of a material object, the role of matter is played by non-matter, and so the structures or compounds constituted from it (namely, divine persons) will be ‘hylomorphic’ only in an extended or analogical sense.
2. In the case of material objects, the form in a particular hylomorphic compound will typically only be contingently instantiated by the matter. Not so, however, in the case of the Trinity. For Christian orthodoxy requires us to say that properties like being a Father and being a Son are essentially such as to be instantiated by the divine essence.
3. The relation of accidental sameness on which our solution is modeled is, in Aristotle anyway, paradigmatically a relation between a substance (e.g., a man) and a hylomorphic structure built out of the substance and an accidental property. The Persons, however, are not like this. Thus, it is at best misleading to say that the relation between them is one of accidental sameness. Better instead to go with the other label we have used . . . . : the persons stand in the relation of numerical sameness without identity.
While acknowledging these disanalogies, R-B think that they are of little import. They conclude:
It seems not at all inappropriate to think of the divine Persons on analogy with hylomorphic compounds; and once they are thought of this way, the problem of the Trinity disappears. Return to the analogy with material objects: According to the Aristotelian solution to the problem of material constitution, a statue and its constitutive lump are two distinct hylomorphic compounds; yet they are numerically one material object. Likewise, then, the Persons of the Trinity are three distinct Persons but numerically one God.
R-B’s account does not wear its interpretation on its face. Some careful exegesis is required if we are to understand the purported analogy.
What, to begin with, do R-B mean by “the divine essence”? They surely do not mean, one thinks, that the divine essence is a sort of immaterial stuff which is formed into the Trinitarian persons, as the analogy with hylomorphism suggests. This is surely to press the matter/form analogy too far. On the orthodox view God is not composed out of any sort of stuff, and it is difficult in any case to make sense of immaterial stuff (as opposed to an immaterial substance or thing). So charity would seem to demand that we interpret the “divine essence” to designate something other than the stuff of which the Father, Son, and Spirit are composed.
But in fact R-B do mean to affirm that the divine essence is the stuff out of which the Trinitarian persons are “made.” In personal correspondence, Rea explains, “Actually, we are suggesting that the Persons are composed of the divine essence plus some form . . . . The idea is that the divine essence plays the role of ‘commonly shared matter’ among the Persons, and the Persons stand to one another in the relation of NSWI [Numerical Sameness without Identity].”
But in this case, the first disanalogy they note—that the role of matter is played by non-matter—looms exceedingly large. Rea avers:
All we mean to commit ourselves to is the idea that maybe the Persons are like a hylomorphic structure: there’s something (we call it ‘the divine essence’ to connect with the portions of the tradition that say that the Persons are ‘of one essence’ or ‘of one substance’; but you could call it something else if you like) that plays the role of commonly shared matter, and, for each Person, something else that plays the role of form.
This explanation fails to allay one’s misgivings. When the tradition affirms that the persons of the Trinity are of one essence or substance, it did not mean to affirm that there is some common stuff or substratum shared by the persons, but rather that the persons share the same generic nature or are one being. The latter interpretation corresponds to Aristotle’s primary sense of “substance” and the former to his secondary sense of “substance.” The affirmation of the Council of Nicea that the Father and the Son are homoousios could be understood to mean that they share the same essence and are therefore equally divine. But the persons of the Trinity are not like three distinct men who all share the same generic essence of manhood; rather they are also one substance in the sense that they are one subsisting thing, one God, not three Gods. What the tradition did not mean was that God or the persons of the Trinity were composed of some sort of spiritual stuff.
In fact, the adoptionist Paul of Samosata, according to the accounts given by Basil and Athanasius, tried to pin on the partisans of Nicea precisely the charge that their use of homoousios with respect to the Father and the Son implied that the Father and the Son have a common constitutive substance, which even Paul took to be absurd. Basil vehemently rejects any such implication:
For they [Paul’s sympathizers] maintained that the homoousion set forth the idea both of essence and of what is derived from it, so that the essence, when divided, confers the title of co-essential on the parts into which it is divided. This explanation has some reason in the case of bronze and coins made therefrom, but in the case of God the Father and God the Son there is no question of substance anterior or even underlying both; the mere thought and utterance of such a thing is the last extravagance of impiety.
In the case of the persons of the Trinity or God there is just nothing analogous to the role played by matter in material things. Indeed, as already mentioned, the idea of an immaterial stuff, of which God or a divine person consists, seems scarcely intelligible. At a minimum, R-B owe us a fuller explanation of how the divine persons can be taken to be analogous to hylomorphic compounds.
Once we understand that R-B do mean to affirm that the divine essence is a sort of stuff of which the Trinitarian persons consist, then the analogy they draw with hylomorphic compounds becomes clear. The divine essence is like matter, and that is why it is not a thing. The divine essence is not like the hand or the man which are formed respectively into the fist or the seated man, for that would require the divine essence to be both a thing in its own right and numerically the same as but not identical with each divine person, which would not solve the problem of the Trinity and is not what R-B want to affirm. That is why in their third disanalogy R-B point out that their solution differs from their paradigm examples of material constitution in that Trinity does not involve a relation between a substance and a hylomorphic compound (whether the relation is accidental or essential is incidental to the disanalogy). Rather the divine essence is like unformed matter and when imbued with the relevant personal form constitutes a Trinitarian person. So each person is like a hylomorphic compound, just as the hand and the fist are each compounds formed out of a common matter. So far numerical sameness without identity does not enter the picture.
That peculiar relation comes into play when R-B assert that “the Persons of the Trinity are directly analogous to particulars that stand in the familiar relation of material constitution.” The particulars they refer to here are things like the hand and the fist, and the familiar relation referred to is presumably the relation of numerical sameness without identity, in which the hand and fist stand to each other. Composed of a common matter, the hand and the fist are two different things which are nonetheless one object. Analogously, the persons of the Trinity, composed of a common divine stuff, are three different things (persons) which are nonetheless one object (God).
So what R-B want to say is that the relation between the Father and the Son, for example, is like the relation between the hand and the fist: numerical sameness without identity. The Father, Son, and Holy Spirit are distinct entities but count as one object, which is God. Just as the hand and the fist are composed of the same matter plus an accidental form, so the persons of the Trinity are composed of the same divine essence plus certain person-individuating properties. So in the Trinity we have a sort of immaterial stuff constituting three persons who are numerically the same object while being non-identical.
Further interpretive difficulties arise. In their second disanalogy to typical cases of material constitution, R-B claim that Christian orthodoxy requires them to say that properties like being a Father are essentially such as to be instantiated by the divine essence. Is this what R-B really want to say? The claim appears to assume that being a Father is a transcendent or Platonic universal which essentially exemplifies the second order property of being instantiated by the divine essence. This does not, however, preclude this property’s being exemplified by something else as well. If we adjust the second-order property to be being instantiated only by the divine essence, then the case of the Trinity is not disanalogous to material objects, because the property, e.g., being Michelangelo’s ‘David’ plausibly exemplifies essentially the second-order property being instantiated only by such-and-such marble, i.e., the statue could not have been made of wood or ice. What R-B want to say, I think, is that the divine essence has the essential property of being a Father. But if the divine essence is the Father, then why would the divine essence not be identical with the Father? The indefinite description “a Father” cannot be taken to fail to designate uniquely God the Father, if we are to have an orthodox doctrine of the Trinity. If some matter has essentially the property of being a particular statue, then it is identical to that statue. It might be thought that one could avoid this problem by holding that the divine essence exemplifies other essential properties peculiar to itself and so is not identical with the Father. But the difficulty with this reply is that that does not seem to be possible on the R-B view. R-B, on the other hand, cannot allow the divine essence to be identical with the Father, for it is not an object, and if it were then the transitivity of identity would imply the Father’s identity with the Son. What R-B want to say is that the divine essence has the essential property, not of being a Father, but rather of constituting a Father. The divine essence essentially constitutes but is not identical with its object. It would be as though some gold essentially exemplified the property constituting the last-minted U.S. twenty-dollar coin or some marble essentially exemplified the property constituting Michelangelo’s ‘David.’
R-B believe that once we think of the divine persons on the analogy of hylomorphic compounds, the problem of the Trinity disappears. But this is far too quick. For the unity and diversity in material constitution do not seem at all analogous to the unity and diversity in the Trinity. In the case of material constitution, we are supposed to come to see that a hand and a fist, for example, or a lump of marble and a statue, are two non-identical things which count as one material object. The analogy to this is that the Father, for example, though non-identical with the Son, is numerically the same spiritual object as the Son. This analogy will hold for each of the divine persons. Of each one it can be said that it is not identical with but numerically the same spiritual object as the other divine persons.
But this does nothing to resolve the Trinitarian aporia. It does not tell us how seemingly mutually exclusive hylomorphic compounds can be numerically the same object. We are told that one object can be both a hand and a fist. All right. But how can one object be simultaneously a clenched fist and an open hand? How can a quantity of gold be at once a U.S. twenty-dollar coin and a Spanish doubloon? How can Socrates be at once seated Socrates, standing Socrates, and reclining Socrates? How can the Winged Victory and the David and the Venus de Milo be numerically the same object? These are the correct analogies to the Trinity, where the same spiritual object is said to be at once the Father and the Son and the Holy Spirit.
Work on the use of personal indexicals in recent decades has served to highlight strikingly the exclusivity and privacy of the first-person perspective. Others may know that William Craig is the second child of Mallory and Doris Craig, but I alone can know that I am the second child of Mallory and Doris Craig; no one else can access my first person perspective nor can this same knowledge be reduced to a third-person perspective. Thus, among the three persons of the Trinity there are three irreducible and exclusive first-person perspectives which not even the classic doctrine of perichoreisis can dissolve. The Father knows, for example, that the Son dies on the cross, but He does not and cannot know that He Himself dies on the cross—indeed, the view that He so knows even has the status of heresy: patripassianism. Thus how the three persons of the Trinity can be numerically the same spiritual object remains as mysterious and problematic as how three statues can each be one and the same material object.
R-B admit that the explication:
(R1) x is a God iff x is a hylomorphic compound whose matter is some divine essence; x is the same God as y iff x and y are each hylomorphic compounds whose matter is some divine essence and x’s matter is the same matter as y’s; and there is exactly one God iff there is an x such that x is a God and every God is the same God as x
when taken all by itself and in isolation is apt to appear “just as mysterious as the conjunction of T1-T3.” But they claim that “much of the mystery goes away” once we appreciate the parallelism of (R1) to a principle concerning material constitution, namely:
(M2) x is a material object iff x is a hylomorphic compound; exactly one material object fills a region R iff at least one hylomorphic compound fills R; and x is (numerically) the same material object as y iff x and y are hylomorphic compounds sharing the same matter in common.
It seems evident that the mystery remains unrelieved by this parallel. (M2) tells us that the David and a marble lump are each a material object; that they are numerically the same object just in case they share the same matter; and that if both of them fill R there is only one object that fills R. But it remains wholly obscure how the David and the Venus de Milo could share the same matter and so be numerically the same material object or how they could both fill R. But this is the sort of thing that (M2) must render intelligible if it is to elucidate (R1), which means to explicate the Father’s being the same spiritual object or God as the Son. The mystery remains.
R-B proceed to make further problematic claims. They state that their view allows us to say that the Father, Son, and Holy Spirit are each identical with God, and yet they are mutually distinct. This is due to the ambiguity of the sortal term “God.” Again they appeal to the analogy of material constitution. Imagine two hylomorphic compounds, like a statue and a marble lump, filling the region R. What is the material object that fills R? R-B reply that it is both a statue and a lump. The expression “the object that fills R” is ambiguous and can refer to either the statue or the lump. Thus, the David is identical to the material object in R, and so is its constitutive lump of marble, but the David is distinct from the marble lump due to the ambiguity of “the material object in R.” Analogously, the sortal “God” is ambiguous. When one says the Father is identical with the spiritual object which is God, one picks out a distinct entity from what is picked out when one says the Son is identical with the spiritual object which is God, even though numerically these are the same object.
R-B’s claim that each of the divine persons is identical with God is very problematic. Prima facie it contradicts their earlier assertion that on their view (T2) is not to be interpreted as the affirmation that each of the persons “is absolutely identical with God,” but rather as an affirmation of numerical sameness without identity. So which is it? A charitable interpretation would be that these two interpretations are affirmed to be equally viable, alternate readings of (T2) on the R-B view. On the identity interpretation, the relation of numerical sameness without identity obtains only between the persons of the Trinity, but not between each person and the spiritual object called God. The relation between each person and that object is absolute identity, but due to the ambiguity of the term “God” arising from relations of numerical sameness without identity between the persons of the Trinity, different entities are picked out by various Trinitarian identity statements like “The Father is God,” “The Son is God,” and so on, and so transitivity of identity does not come into play. By contrast on the numerical sameness without identity interpretation, relations of numerical sameness without identity are said to obtain not only between the persons of the Trinity, but also between each person and the spiritual object called God. Each person is said to be numerically the same as but not identical to the object God, as well as each other. Curiously, R-B have said almost nothing to motivate this latter interpretation, though they give it pride of place, since they have concentrated on analyzing the inter-personal relations in the Trinity in terms of numerical sameness without identity, not the relations between the persons and the spiritual object God.
Difficulties persist. In the first place, even if “the object that fills R” is ambiguous when referring to the David or its constitutive lump of marble, it is not ambiguous when it comes to picking out either the David or the Winged Victory. The David and the lump can both fill R and so be ambiguously referred to by “the object that fills R.” But the David and the Winged Victory cannot, to all appearances, both fill R, so there is no ambiguity in their regard. Similarly, is it not implausible to think that “God” is ambiguous when it comes to the Father and the Son? Given the exclusivity and privacy of the first-person perspective, persons are as impenetrable as statues. So how could they both fill R? Parity would suggest that just as in the case of the David and the Winged Victory we have two material objects, so in the case of the Father and the Son we have two spiritual objects, two Gods,
Second, R-B explain that due to the ambiguity of the phrase “the object that fills R,” there is no correct answer to the question of what are the essential properties of the object in R. One has to disambiguate before answering the question concerning what the essential properties of the object are. But this seems to imply that the question as to the essential properties of the spiritual object called “God” is equally unanswerable. That question can be answered only relative to some disambiguating description. But this seems to be the very feature of Relative Identity which R-B pronounced “catastrophic” and “disastrous” when applied to the Trinity. The numerically same object can be either identical to the Father or identical to the Son dependent upon how we choose to describe it. But R-B rejected Relativity Identity because “we do not want to say that the very existence of the Father, Son, and Holy Spirit is a theory-dependent matter. Nor do we want to say that the distinction of the Persons is somehow relative to our ways of thinking or theorizing. That appears to be a form of modalism.” It is hard to see how R-B can avoid a similar charge. They might say that the Father and Son are really non-identical on their view, but that our linguistic terms “Father” and “Son” are ambiguous in their reference. But then it is inaccurate to say that statements like “The Father is identical with God” are true, for the terms do not unambiguously refer. If the statements are true and the ambiguity is ontological, then one does seem guilty of making identity relative to one’s thinking or theorizing.
In sum, the disanalogies between the Aristotelian account of material constitution and the doctrine of the Trinity seem so great that appeal to that account does little to illuminate the Christian doctrine. If anything, the analogy of material constitution ought to incline us to think that the divine essence cannot constitute the Father, Son, and Holy Spirit at once. All this has been said on the assumption that the strange doctrine of numerical sameness without identity is metaphysically acceptable, which assumption is, it scarcely needs to be said, moot. I do not intend these criticisms of the R-B proposal as a refutation of the model so much as an invitation to further reflection on it. Rea and Brower have offered us a provocative, new way of understanding the Trinity, but they still have a lot of explaining to do before their interpretation becomes illuminating or plausible. I hope that these brief criticisms will be a spur to further exploration of their model. In the meantime I have elsewhere offered a quite different social model of the Trinity which I venture to think escapes all their criticisms of Social Trinitarianism.
 John Perry, "The Problem of the Essential Indexical," Noûs 13 (1979): 3-29; idem, "Frege on Demonstratives," Philosophical Review 86 (1977): 474-497; idem, "Castañeda on He and I," in Agent, Language, and Structure of the World, ed. James E. Tomberlin (Indianapolis: Hackett Publishing, 1983), pp. 15-42. For discussion, see David Lewis, "Attitudes De Dicto and De Se," Philosophical Review 88 (1979): 513-543; Palle Yourgrau, "Frege, Perry, and Demonstratives," Canadian Journal of Philosophy 12 (1982): 725-752; Patrick Grim, "Against Omniscience: The Case from Essential Indexicals," Noñs 19 (1985): 151-180; Howard Wettstein, "Has Semantics Rested on a Mistake?" Journal of Philosophy 83 (1986): 188; William Seager, "The Logic of Lost Lingens," Journal of Philosophical Logic 19 (1990): 407-428.
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 Ibid., p.
 For example, I should like R-B to reflect on the implications of their view for diachronic identity. All of the cases they consider are cases of synchronic identity. For example, the hand, when clenched, is said to be at once a hand and a fist. These two things are non-identical entities but are numerically the same material object. So what about the case in which the hand is open at t1 and clenched at t2? It seems that the first material object is not identical with the second. This is to deny diachronic identity and intrinsic change. Perhaps it could be said that the object at t1 is identical with the object at t2 once the latter is disambiguated and described as a hand. But then, paradoxically, the hand has not changed from t1 to t2! For qua hand it remains the same. Rather a new being has come into existence at t2 along with the hand, namely the fist, which is not identical to the hand. Thus, intrinsic change seems to be impossible.