Justified True Belief

(●) God is best modeled as one immaterial soul carrying three complete sets of rational faculties. + Everybody in the debate agrees on what has to be accounted for: one God, three persons, three who address one another. What is on offer is a model, a proposal about how all of that could be true together, and a model earns its place by fit rather than by proof. The one to prefer covers the most evidence while inventing the fewest extra parts. The proposal is a single spirit equipped three times over: one substance, and so one God; three centers of thought, will, and self-awareness, and so three persons. Two rivals stand against it, the accounts that make the persons three substances and then have to talk their way back to one God, and the account that gives the name "God" to the Trinity as a whole rather than to an individual. Who holds what, on the model: - Support: William Lane Craig, whose model this is and whose name for it replaced Brian Leftow's, with J. P. Moreland. Tertullian's three persons in one substance is the classical formula it gives a clear sense to. - Oppose: Michael Rea, who says the model cannot confess the creed's first line. The argument that follows defends it.

(P1) The one God is three distinct persons. + Christians confess one God in three persons, and the whole difficulty is holding both halves at once. Tripersonal Monotheism is a proposal about how it can be done. (1) The doctrine is two sentences long. - There is exactly one God. There are exactly three distinct persons, the Father, the Son, and the Holy Spirit, each of whom is properly called God. Every rule the church has ever set around the Trinity is a guard on one of those two sentences. - The first sentence is Israel's confession, the Shema, which observant Jews still say morning and evening: "Hear, O Israel: The LORD our God, the LORD is one" (Deuteronomy 6:4). "I am the first and I am the last; besides me there is no god" (Isaiah 44:6). - The second is the New Testament's habit. Converts are baptized into one name belonging to three (Matthew 28:19). A letter closes with a blessing from three (2 Corinthians 13:14). Thomas says "My Lord and my God!" to Jesus and is not corrected (John 20:28), and lying to the Holy Spirit is lying to God (Acts 5:3-4). - Think of a two-line creed pinned to a kitchen corkboard. Take the first line down and you have a crowd of gods; take the second down and you have a lone God wearing three names. (2) The three say "I" and "you" to one another. - At the Jordan the Son comes up out of the water, the Spirit comes down on him, and a voice from heaven says, "You are my beloved Son" (Mark 1:9-11). Count the parties. One is baptized, one descends, one speaks. - "Father, glorify me in your own presence with the glory that I had with you before the world existed" (John 17:5). That is a request, from someone, to someone, for something. - Philosophers have three words for what speech like that requires. • Self-consciousness is being aware of yourself as yourself: the jolt of catching your reflection in a shop window and realizing the tired man in it is you. • Intentionality is the aboutness of a mind. You never merely believe; you believe that the kettle is on. • Volition is the power to settle on something and do it. - A person is a center of all three, and the Gospels show three such centers in conversation. (3) Before Bethlehem, the three had no bodies. - "God is spirit" (John 4:24), and a spirit, as the risen Jesus puts it, "does not have flesh and bones" (Luke 24:39). The Son had glory with the Father "before the world existed" (John 17:5), long before there was any flesh for him to take. - Three brothers are three men, and nobody wonders why. Three bodies, three men. Now take the bodies away and ask what makes three minds one being rather than three, and no obvious answer is waiting. - So before the Incarnation, before God the Son took a human body and a human life, the three were minds without bodies, and whatever made them one was not a body. (4) A model is a proposal about how something could be. - Told that a footbridge "cannot possibly" carry a marching band, an engineer answers by drawing one design that would. She has not built the bridge. She has shown that the "cannot" was false. - A model of the Trinity works the same way. It answers to the doctrine rather than the other way round, since the doctrine comes from Scripture while the models come from philosophers. - Several models are on offer, and choosing between them is detective work rather than proof. A detective does not deduce the culprit the way one proves a theorem. He asks who best accounts for everything on the table at once, and here the evidence is one God, three persons, and three who address one another. The model to prefer covers all of it without inventing extra parts. Therefore, the one God is three distinct persons, which leaves one question standing: what makes three bodiless persons one being.

(P2) A soul is an immaterial substance. + The model is built out of the oldest thing Christians say about God: he is spirit. Getting clear on what a spirit, or a soul, is does most of the work. (1) A substance is a thing that exists in its own right. - Philosophers sort what there is into things and the features of things. Your dog is a thing. Her brown color, her weight, and her being asleep are features of her, and they exist nowhere except in her. A substance is a thing of the first kind: something that exists on its own and carries its features rather than being carried. - Relations are passengers of the same sort. Your dog is heavier than the cat. That "heavier than" is real, and it is not a third animal in the house. - The test is the moving van. When you move house you take the sofa. You do not take the sofa's shabbiness separately, wrapped in its own blanket. Substances get carried; features and relations ride along. (2) A soul is a substance that is not made of matter. - Immaterial means not composed of physical stuff: no atoms, no mass, no location you could point at. A soul is the immaterial substance that thinks, chooses, and stays one and the same self across a lifetime. - Consider what stays the same in you. Most of the atoms in your body were somewhere else a decade ago, your memories have shifted, your opinions have changed, and you can still be held to a promise you made at nineteen. Whatever bears that continuing responsibility is what the word soul is reaching for. - Some Christians doubt that human beings have souls in this sense, holding that a person is a living body and nothing more. That dispute is real, and the model needs nothing from it. What the model needs is that God is an immaterial substance, and the human soul comes in only as the case we know from the inside. (3) God is spirit. - Jesus says so to a Samaritan woman who wanted to know which mountain was the right one for worship: "God is spirit, and those who worship him must worship in spirit and truth" (John 4:24). He is "the King of the ages, immortal, invisible" (1 Timothy 1:17). No body, no location, no matter. - He is a someone rather than a force. He knows, he decides, and he keeps his word: "My counsel shall stand, and I will accomplish all my purpose" (Isaiah 46:10). A thing that knows and decides and is not made of matter is an immaterial substance, whatever else you want to call it. - The Fathers guarded that word carefully. In the third century a bishop named Paul of Samosata read homoousios, Greek for "of one substance," as meaning that the three were made of one divine material, three portions cut from a common stuff. Basil rejected that reading vehemently (Epistle 52.1), and Athanasius said the trick lay in taking the word "in a bodily sense" (De synodis 45). (4) An immaterial substance is a thing, not a spiritual stuff. - A lump of clay is stuff. A pot is a thing. Stuff comes in amounts and can be divided into portions, while a thing is one, and is either there or not. - Immaterial stuff, a spiritual clay that could be ladled out into portions, is hard to make any sense of. An immaterial thing is not hard at all: a mind that is not a body. - So when the model says God is one soul, it is saying that God is one thing, one individual, rather than a quantity of divine material that three persons were cut from. That is exactly the misreading the Fathers refused. Therefore, a soul is a thing that exists in its own right and is not made of matter, and God is such a thing.

(P3) Rational faculties are what make a soul a person. + What makes a soul a person is not that it is a soul. It is what the soul is equipped to do. (1) A faculty is a standing power to do something. - A woman under anesthesia can neither see nor decide anything, and she is every bit as much a person as she was an hour before. Her powers of sight and choice are hers, idle for the moment. That is what a faculty is: a capacity a thing has whether or not it is being used, the way a piano can play a C-sharp at three in the morning with nobody near it. - The rational faculties are two. The intellect is the power to know, to reason, to think "I." The will, or volition, is the power to settle on something and act. - A stone has neither. A dog has some of the first and a good deal of the second, and nobody thinks it lies awake wondering whether it has been a good dog. Persons have both, in full. (2) The rational faculties give a first-person perspective. - A first-person perspective is the view from behind your own eyes, the standpoint from which you say "I." Only you occupy it. The smell of coffee in your kitchen this morning was known from the inside by exactly one person. - Intellect and will together are what make that standpoint: a mind that can be aware of itself as itself, that can think about things, and that can determine what it does. Philosophers call the last of these self-determination, and it is the difference between choosing to stand up and being stood up by a nurse. - Whatever has those has a someone in it. Whatever lacks them, however large or old or powerful, has nobody home. (3) The tradition's own definition of a person runs on reason. - The definition the church worked from for a thousand years is Boethius's, written around AD 512: a person is "an individual substance of a rational nature" (Contra Eutychen 3). Thomas Aquinas takes it up in the 1260s, tests it clause by clause, and asks whether it can be said of God at all (Summa Theologiae 1a.29.1, 1a.29.3). - A rational nature is simply a nature with intellect and will. So the idea that the rational faculties are what make a person is no piece of modern psychology smuggled in. It is the tradition's own account, and the model takes that half of the definition over whole. - The other half, "individual substance," is the hard one. The model denies that each person is a separate substance of his own, and that denial draws the sharpest objection anyone brings against it (D8). (4) A soul with one set of rational faculties is one person. - You have one intellect and one will, and so exactly one "I." That is why you are one person and not two, however divided you may feel about the second slice of cake. - Arguing with yourself in the shower does not change the count either. Both sides of that argument are seen from one standpoint, and the "you" being argued with is the same "I" doing the arguing, which is the difference between a debate and a rehearsal. - Turn the point around and it becomes the hinge of everything that follows. What settles how many persons a soul is, is how many complete sets of rational faculties it bears. Therefore, what makes a person is a complete set of intellect and will, which means the count of persons in a soul is the count of its complete sets.

(P4) One soul with three complete sets of rational faculties is three persons in one substance. + Put P2 and P3 together and a question opens up that never has to be asked about a human being: what if one soul carried more than one set? (1) A three-headed dog gets us to the real question. - Cerberus, in the old stories, guarded the gate of the underworld with three heads. Suppose three heads are normal for his breed, so that he has three brains and three distinct centers of consciousness, which we may as well call Ajax, Atlas, and Hermes. They might well quarrel over a bone. - Nobody counts three dogs. Cerberus is one animal with one canine nature, and when Atlas bites Hercules, Hercules reports that Cerberus attacked him. Three centers of consciousness in one being is at least something we can picture. - Now kill the dog. His body was what made three minds one animal, so let the body die and the minds survive, as many people believe happens to us. Nothing bodily unites them now, and nothing else obviously does either. - That is exactly the situation of the divine persons, who were three minds without bodies before the Incarnation (P1). The dog was only ever a springboard, and this is what he launches: whatever unites three bodiless persons has to be something that does not need a body. (2) One soul equipped three times over is the answer. - Here is the proposal. Suppose that God is a soul endowed with three complete sets of rational faculties, each set sufficient all by itself for personhood. - Run that through P3. Each set is complete, so each yields its own first-person perspective, its own "I," and three centers of self-consciousness, intentionality, and volition are three persons. - Now run it through P2. All three sets are faculties of one soul, one immaterial thing, so there is one substance and not three. - In the words of William Lane Craig, whose proposal this is, God would then be "an immaterial, tripersonal substance, just as each of us is an immaterial, unipersonal substance." The difference between you and God is not a difference in kind of thing. It is a count of sets. (3) Three complete sets are three "I"s, not one "I" in three hats. - Each first-person perspective is exclusive. Nobody else can occupy yours, and no description from outside can stand in for it. Philosophers call this the problem of the essential indexical, after words like "I" that cannot be swapped for a name without changing what is known. - Think of a man following a trail of spilled sugar around a supermarket, hunting for the careless shopper, until he glances down and sees the torn bag in his own cart. "It is me" was news, and no description from outside had delivered it. - So the Father knows that the Son dies on the cross, and cannot know that he himself does. No mask and no mode of appearing produces a difference like that. Three complete sets are three someones, which is why the three can say "you" to one another as they do at the Jordan (P1). (4) The count stops at three. - Not three souls. The faculties are all faculties of the one soul, so there are not three substances joined at the hip, which is the picture critics of social models warn against. There is one substance, three times equipped. - Not a fourth self either. A self just is a complete set of rational faculties in a substance (P3), and there are three sets, so there are three selves and no more. The soul is not a further "I" standing behind the three, any more than you stand behind your own intellect and will. - A committee needs a chairman. A soul does not. Therefore, a soul with three complete sets of rational faculties is one substance and three persons, which is what the Latin church has meant by three persons in one substance since Tertullian.

(C1) Therefore, God can be one soul who is three persons. + A soul with three complete sets of rational faculties is one God and three persons at the same time. Both sentences of the doctrine come out true together, which is exactly what the charge of contradiction said could not happen. (1) Both sentences of the doctrine come out true together. - One substance, so exactly one God (P2, P4). Three complete sets of rational faculties, so exactly three persons (P3, P4). The two sentences are not in tension, because they count different things. - Nothing in the model needs "the Father is God" to mean "the Father is the very same thing as God." The sentence ascribes deity: the Father is a divine person, bearing a complete set of the faculties by which God knows, wills, and loves. - Compare the classical formula, three persons in one substance, tres personae, una substantia, whose vocabulary Tertullian gave the Western church around AD 213 (Against Praxeas 2, 12). The model gives that formula a sense a reader can restate in her own words, which is something it has not always had. (2) Showing one way it could be true is enough. - The critic says the doctrine cannot be true, that one God and three persons contradict each other. One clear way in which both could be true answers him completely, whether or not it happens to be the way things actually are. A single design that would carry the marching band refutes "no design could." - The modesty is deliberate. God can be one soul who is three persons, which is a smaller thing to say than that this is the best account on offer (C2), and a much smaller thing than saying the model was revealed, because it was not. (3) The model is not part of the faith. - Christians believe the two sentences because of what the New Testament says about the Father, the Son, and the Spirit. The model is a philosopher's proposal about how the two sentences fit together, and a Christian is perfectly free to hold the doctrine and decline the model. - Its defenders claim three things for it and no more: that it is straightforward, perspicuous, and explanatorily deep. Easy to state, clear to grasp, and able to answer the next question rather than forbid it. Whether it survives comparison with the rivals is a further question (P5, P6, C2). Therefore, one God who is three persons is a claim with a clear and possible sense, which is all the charge of contradiction ever denied.

(P5) The Father, the Son, and the Spirit are not three divine substances. + The nearest rivals keep the three persons and pay for them with the one God. They make the persons three beings, then have to explain why three beings count as one. (1) Three divine substances in perfect agreement would be three Gods. - The most developed rival is Functional Monotheism: three divine individuals, each a substance in its own right, who cannot fail to cooperate because each is all-powerful and perfectly good. The three function as one, and that is said to be enough. - Give it its due. It takes the three persons with complete seriousness, and its defenders confess the creed as firmly as its critics do. One critic calls it a refined paganism, a phrase that is unkind but not careless. - A committee that never disagrees is still a committee. Three separate Gods, each all-powerful and morally perfect, would cooperate just as perfectly, and nobody would call them one. The Shema is not a claim about how well a board of directors gets along. (2) A divine person caused by another exists the way creatures do. - Functional Monotheism's answer to "why not three Gods?" is that the Father everlastingly causes the Son and the Spirit, so the three have a single source. - But the Son is a distinct substance on this view, which makes bringing him into being a creation out of nothing. He would exist the way creatures exist, held in being by another. That is what Arius saw, the Alexandrian presbyter whom the Council of Nicaea condemned in 325 for teaching that the Son is a creature. - Drop the causing and the other side of the trap closes. There would simply happen to be three divine beings sharing one nature, with nothing whatever to explain why, and a coincidence of that size is not credible. - Its defenders answer that an eternal causing the Father could never have withheld is nothing like the making of a creature, and that difference is real. What it does not remove is the mark of creaturely existence itself, which is being held in being by another. Free or necessary, the one held still has no ground of being in himself, and that is the one thing a creature always lacks and God never does. - Either way the unity is bought with something the doctrine cannot afford: a creature inside God, or a coincidence where a reason should be. (3) Turning subminds into persons kills the self they started from. - A second rival, Group Mind Monotheism, starts from split-brain patients, whose surgeons cut the thick bundle of nerves joining the two halves of the brain in order to control severe epilepsy. In the laboratory such a patient can behave as though two minds share one skull, the left hand doing one thing while the mouth reports another, though researchers still argue about whether that shows two minds or one mind with two channels. - Perhaps, the thought runs, a mind can be a group of subminds, and God is a group mind whose three subminds are the three persons. - To keep the Gospels' "I" and "you," those subminds have to become self-conscious in their own right. But then the original single self-consciousness, presumably the Father, expires in the process, and once three self-conscious minds have emerged nothing explains why they are not three Gods. - The picture is a modern rerun of the second-century Logos doctrine, on which the Word (logos is Greek for "word") lay hidden inside God and was put forth into the world at creation. It inherits the old trouble: persons who come to be, rather than persons who always were. (4) The one-soul model unites the three by what they are, not by agreement. - Three sets of faculties belonging to one substance are one being for the same reason your intellect and your will are one being. They are powers of one thing. No cooperation is needed, and no person has to be caused by another. - Even sharp critics of the model grant this much. Its one soul plays the role the tradition gave to the single concrete divine nature the three share, which puts it nearer the tradition than three divine substances are (D1). Therefore, the three are not three substances held together by agreement or by descent, and any model that makes them so has traded the one God for three.

(P6) God is an individual substance, not a group of three. + One question is still open: what does the word "God" name, on this picture? The answer to it is what gives the view its name. (1) An older label made the Trinity itself the one God. - One family of three-person views travels under the name Trinity Monotheism: the Trinity as a whole is what is properly God, while the persons are divine without being Gods. The attraction is obvious, since the Trinity is the one and only thing with everything it takes to be God. - The idea underneath the label is sound and stays. "The Father is God" ascribes divinity to the Father, the way "my neighbor is Irish" says what she is rather than saying she is the whole of Ireland. And what it takes to be God includes being triune, being three in one, which no single person is. (2) A group is not a substance. - The Trinity does have obvious affinities to a group. It is the Father, the Son, and the Spirit taken together, and a group is nothing over and above its members. But if God simply is that group, then God is a group, and a group of divine persons is Functional Monotheism's three Gods with a collective noun in front of them (P5). - A family is not a fourth person living in the house. It is the three who live there, considered together. (3) "God" names the soul, not the group. - Craig's second thought about the label says it plainly. God is clearly an individual substance, and so an individual rather than a group, while the Trinity is simply the group of the divine persons, which is not itself an individual or a substance at all. Hence the name he gives the view: Tripersonal Monotheism. - Not the group, then, and not a fourth self standing behind the three, but the one soul who is three persons. Monotheism: one God, one individual. Tripersonal: who is three persons. (4) Each person is wholly God without being the whole of God. - Each person has a complete set of the faculties by which God knows, wills, and loves, and so each is all-knowing (omniscient), all-powerful (omnipotent), and perfectly good in his own right, not by courtesy of the other two. - The whole is not a fourth someone, since the soul's selves are exhausted by its three sets (P4, D15). Hilary of Poitiers, writing in the 350s, put it in one sentence: "Each Divine Person is in the Unity, yet no Person is the One God" (On the Trinity 7.2). The model gives that sentence a home. (5) What God is and how the persons are divine are two questions. - Two separate claims travel together here, and keeping them apart matters, because an objection can sink one of them and leave the other standing. - The model answers the first question, what God is. One soul, three complete sets of rational faculties, and nothing more elaborate than that. - The formal theory answers the second, how each person gets to count as divine. Its answer is that the one individual that God is has the divine nature and nothing else does, since that nature includes being triune, and each person is divine as a part of that individual. A second route is available instead, on which each person is divine by having the attributes only God has. - The two come apart cleanly. A reader may hold either without the other, and the published objections have concentrated on the theory while leaving the model where it stood (D10). So when an objection arrives, the first thing to ask is which of the two it lands on. Therefore, "God" names one individual substance, "the Trinity" names the three persons who are that substance's three selves, and the view earns the name Tripersonal Monotheism.

(C2) Therefore, God is best modeled as one immaterial, tripersonal substance. + Of the accounts on the table, one soul with three complete sets of rational faculties fits the evidence best and invents the least. (1) The model keeps both sentences without straining either. - Judge it the way you would judge a doctor's diagnosis. How much of the trouble does one account cover, and how many extra conditions does it have to invent? Three-substance models cover the three persons, then need a second story, cooperation or causation, to get back to one God, and neither story arrives (P5). - The one-soul model covers both with a single idea. One substance is why there is one God. Three complete sets of faculties is why there are three persons. - It invents no new material either. God is spirit (P2), a person is a substance with a rational nature (P3), and all the model adds to those old parts is a count. (2) The one-self accounts fail in the other direction. - A one-self account says that Father, Son, and Spirit are one and the same "I" under three descriptions. The most careful of them, Aquinas's, makes the persons subsisting relations: fatherhood and sonship existing as things in their own right, really distinct because being a father and being a son are opposed. - Opposed relations do distinguish, and that should be granted. What they do not do is pray, send, love, and obey, and the Gospels are full of all four. - The boldest one-self account makes God a single self living three overlapping lives. Then Gethsemane, where the Son prays "not what I will, but what you will" (Mark 14:36), turns into a soliloquy: one man alone on a stage, talking to himself. - Both keep the Shema and lose the Jordan, where three parties are present at once. What the evidence calls for is three centers of self-consciousness in one being. (3) The logical repairs mend the sentence and leave God undescribed. - A third family accepts that "the Father is God" states an identity and then adjusts logic or metaphysics to survive it. Relative identity says the three are the same God without being the same person. Numerical sameness without identity says the persons share the divine essence the way a statue and a pillar can share one block of marble. - The marble is the trouble. Give the divine essence the part the marble plays and it becomes a stuff that the persons are made out of, which is the reading Basil and Athanasius refused (P2). - Neither repair delivers three exclusive first-person perspectives, which is what the Gospels put in front of us (P4). Neither says what God is. Both say how to speak about him without contradiction, and that is worth having without being a model. (4) The model comes with a bill. - Two items on it are later formulations the model sits loose to. Eternal generation, the creed's teaching that the Son is eternally begotten of the Father, is no feature of the model, though nothing in the model rules it out, and a Christian who holds the begetting may add it (D7). - Divine simplicity, the classical teaching that God has no parts and no internal distinctions, asks in its strongest form for more than three sets of faculties allow, and more than any account of three distinct persons has managed to give it (D6). - Both of those are disputes inside orthodoxy, among people who confess the same creed, and the model settles neither one. - The third item is a plain admission. No human case shows a soul carrying more than one set of rational faculties. The claim is that the arrangement is possible for God, not that anyone has ever seen it. (5) What would defeat it. - A proof that one substance can bear at most one set of rational faculties would sink the model, and this conclusion with it, though not the doctrine. Showing that "person" must mean a separate substance, so that three persons are always three things, would do the same. - A demonstration that the model contradicts Scripture, rather than contradicting a later formulation, would end it for a Christian at once. Inconsistency with a creed is a cost. Inconsistency with the text is a refutation. Therefore, God is best modeled as one immaterial, tripersonal substance, and the doctrine as Scripture states it is not merely free of contradiction but straightforwardly modeled. See also: PT / The Trinity: One God in Three Persons PT / The Trinity: Anti-Social Trinitarianism PT / The Trinity: Relative Identity and Constitution PT / The Trinity: The Logical Problem of the Trinity PT / The Trinity: Trinity Monotheism