Justified True Belief

(P1) A contradiction affirms and denies the same thing of the same subject in the same sense. + Christians confess that there is exactly one God, and that three distinct persons, the Father, the Son, and the Holy Spirit, are each fully God. The charge philosophers call the logical problem of the Trinity is not that this is hard to picture but that it cannot be true, and settling a charge like that means knowing exactly what a contradiction is. (1) A contradiction is one specific failure, not general strangeness. - The rule is old and nobody has improved on it. Aristotle put it this way: the same thing cannot both belong and not belong to the same thing at the same time and in the same respect (Metaphysics IV.3). Philosophers have called it the law of non-contradiction ever since. - Say of one front door, at one moment, both "the door is open" and "the door is not open." Those cannot both be true, and you can see it without knowing the first thing about doors. That is a contradiction, and it is the only thing the word means. - Now change one small detail. "The door is open" and "the window is not open" collide nowhere, because they are about different things. "The door was open at noon and shut by three" collides nowhere either, because it is about different moments. The collision has to be exact, and where it is not exact there is no collision at all. (2) The "same sense" clause carries most of the weight. - Picture a man back from a fishing trip who tells you, in the same week, both "I sat down on the bank" and "I did not sit down on the bank." On paper that is a flat collision. If the first bank is the muddy edge of a river and the second is the branch office where he keeps his money, both sentences are true and nothing whatever has gone wrong. - Using one word in two senses inside a single argument, while treating it as one word, is called equivocation. The textbook case is "only man is rational; no woman is a man; therefore no woman is rational," which trades entirely on "man" meaning the whole species in one line and the male half of it in the next. - So anyone bringing a charge of contradiction carries a second burden along with the first. He has to show that the colliding sentences use their key words in one steady sense, because if the key word shifts underneath him, the two sentences were never about the same thing to begin with. (3) Failing to picture something is not the same as finding it impossible. - Plenty of true things resist a mental picture. Nobody can picture a thousand-sided figure clearly enough to tell it apart from a nine-hundred-and-ninety-nine-sided one, and no one has ever concluded from that failure that one of the two shapes is impossible. - Physicists gave up demanding a picture of light a long time ago and kept the mathematics instead, because the equations stayed consistent even where the imagination ran out. That was not intellectual cowardice. It was noticing which complaint was which. - Think of it this way: a mechanic who lifts the hood and says "I can't see how this engine runs" has not shown the car is standing still. "I cannot follow it" and "it cannot be true" are two different reports, and only the second one is an objection. Therefore, the charge is a precise one, and it succeeds only where the same thing is affirmed and denied of the same subject in the same sense.

(P2) "Is" does not always mean "is identical to." + Everything in this dispute hangs on a two-letter word. As it happens, that word does at least three different jobs, and English never marks which one is in play. (1) The "is" of identity puts two names on one thing. - "Mark Twain is Samuel Clemens." One man, two names, and the sentence is telling you that both names land on the same person. - Identity has a test you can actually run, which is that the names swap freely. If Twain is Clemens, then Clemens is Twain, and anything true of the one is true of the other right down to the last detail. • That test has a name. Leibniz's Law, after the philosopher who stated it, says two things are identical only if every property of the one is a property of the other: same birthday, same height, same debts, same handwriting, all the way down the list. • Identity carries two further features worth holding on to (P4). It is symmetric, which means it runs in both directions. And it is transitive, which means that if A is B and B is C, then A is C, whether or not anybody notices. (2) The "is" of predication hangs a property or a title on something. - "Peter is human." To predicate something is to say what a thing is like, or what it counts as, rather than which particular thing it is. Nobody hears that sentence as two names for one item, and nobody comes away thinking that everything human is Peter. - Titles work the same way, and the Old Testament has a case worth keeping in mind. Belshazzar is called king of Babylon. That does not make Belshazzar and the kingship one thing, and it leaves room for somebody else to hold the title at the same time. As it happens, somebody did. Belshazzar ruled alongside his father Nabonidus, which is the likeliest reason that the best honor he could offer Daniel was to be "the third ruler in the kingdom" (Daniel 5:16). Second place was already taken, by him. - Predication does not run backwards, either. "Peter is human" is true, and "human is Peter" is not a sentence anybody would ever utter. (3) The "is" of constitution says what a thing is made of. - "The statue is the block of marble." Fair enough, as far as it goes. And yet the block sat in the quarry for a year before there was any statue at all, and it would still be sitting there after a hammer had finished with the statue. - The two occupy the same space and weigh the same, and they are still not simply two names for one item, since one of them outlives the other. Whatever the little word is doing in that sentence, it is not the job it does in "Twain is Clemens." (4) Ordinary speakers move between the three without noticing. - "That is my brother" points at one man twice. "That is a doctor" hangs a profession on him. "The ring is gold" says what it is made of. One grammar, three logics, and not a single listener stumbles. - Trouble starts only when somebody insists that a sentence must be doing the first job because it happens to wear the same clothes as the other two. Therefore, before anything at all follows from "the Father is God," somebody has to establish which of these three jobs the little word is doing.

(P3) The logic of a sentence cannot be read off its grammar. + Grammar is a poor guide to logic, and that is one of the first things a student of logic is taught. (1) Sentences of the same shape can behave in wholly different ways. - "Mary is a doctor" and "Mary is the doctor who treated me" are built alike and work differently. The first hands her a profession. The second picks out one individual in a crowd and says that Mary is that one. Change a single word and the logic underneath changes with it. - None of this was invented for a dispute about the Trinity. The gap between the shape of a sentence and the logic underneath it is a standard finding in philosophical logic, and it is a good deal older than the dispute. (2) Grammar will cheerfully assemble nonsense. - "Nothing is better than eternal happiness. A cheese sandwich is better than nothing. So a cheese sandwich is better than eternal happiness." Every step is good English, and the conclusion is a joke, because "nothing" was never the name of anything. - Or take "the average family has 1.7 children," a perfectly formed sentence about no family anywhere on earth. The grammar hands you a subject. The world does not always have one to match. (3) Assuming that every "is" asserts identity is a known mistake with a name. - Two expressions co-designate when they point at the same item, the way "the morning star" and "the evening star" both turn out to point at Venus. The mistake is assuming that any sentence joining two expressions must be claiming they co-designate. - Suppose your neighbor mentions on Monday that his car is a Ford, and mentions the following week that his wife's car is a Ford. You do not conclude that the couple share one vehicle. You take "is a Ford" for the kind of remark it obviously is. - Applied to the Trinity, the mistake looks like this: because the New Testament says the Father is God, it must mean that "the Father" and "God" are two names for one and the same item. Assuming is the operative word there. Nobody has shown it. (4) Which reading a sentence takes is settled by use. - You learn what a sentence means by watching what its author does with it: what he infers from it, what he pointedly refuses to infer, and what else he is willing to say in the same breath. - That is not a lower standard than logic, and it is not a softer one. It is the only way logic ever gets applied to a text, because logical form is something a sentence has rather than something it wears on the outside where anyone can read it off. Therefore, whether the biblical statements assert identity is a question about how the men who wrote them actually used them.

(P4) The New Testament does not use "the Father is God" and "the Son is God" as identity statements. + If those sentences were equations, the men who wrote them would have handled them as equations. They do the opposite, and they do it consistently. (1) They never once turn the sentence around and say God is the Son. - Identity is symmetric, so reversing it costs nothing. If Twain is Clemens, then Clemens is Twain, and either sentence will do. - The New Testament says the Word was God (John 1:1). It has the Father address the Son as "God" outright: "Your throne, O God, is forever and ever" (Hebrews 1:8). It lets Thomas say "My Lord and my God" to a man standing in front of him (John 20:28). Not once does it turn the sentence around. - The care runs deeper than one missing sentence. These writers never call Jesus "Father," and they never hand him the compound Old Testament name "the LORD God." Across twenty-seven documents the distinction between the persons is nowhere breached, and men writing equations would have had no reason to watch their wording that closely. (2) One writer hands the title "true God" to two different subjects. - "This is eternal life, that they know you the only true God, and Jesus Christ whom you have sent" (John 17:3). From the same hand, a few pages later: "he is the true God and eternal life" (1 John 5:20), which most recent commentators, though not all, read as a statement about Christ. - Strict identity cannot hold both at once. If the Father alone is the true God, and Jesus is the true God, then the two collapse into one person, and the first verse has just distinguished them by name. - The writer shows no sign of a difficulty, and his own sentence says why. "The only true God" is set against idols, as that phrase always is in Scripture. It is not set against the Son, who is named in the same line as the one God sent. (3) Nobody in the New Testament draws the inference identity would force. - Transitivity does the work in one line. If the Father is God and the Son is God, and both are identities, then the Father is the Son. A schoolchild could draw it. - No writer draws it. Not in a Gospel, not in a letter, not once. And it is not as though they avoided the subject: the Father sends the Son (John 3:17), the Son prays to the Father (John 17:5), the Father speaks from heaven about the man standing in the river (Luke 3:21-22). - Of course, silence is thin evidence where a writer had no occasion to speak. Here the occasions are everywhere, in documents from different hands written two generations apart, by authors who disagree with one another about plenty else. When a conclusion is that short and that important, and nobody in a whole literature ever reaches it, the best explanation is that their sentences never licensed it. (4) John's opening line blocks the identity reading in a single breath. - "In the beginning was the Word, and the Word was with God, and the Word was God" (John 1:1). Two clauses, one sentence, one breath. The Word was with God and was God, and nothing is with itself in that sense. - In the Greek of that last clause the word for God carries no "the" and stands ahead of the verb. A noun placed that way usually says what something is rather than which one it is, and that is how grammarians read the line: the Word has everything it is to be God, and is still not the one he was with. - That is a habit rather than a slip. Time after time, where Christ is called God, the same passage distinguishes him from the Father in the same breath. Writers laying down an equation do not undercut it on the very line where they lay it down. Therefore, the men who wrote these sentences used them in ways identity does not permit, and a reader who imports the identity relation is adding something they never put there.

(C1) Therefore, the doctrine of the Trinity contains no contradiction. + (1) Written out in full, the doctrine's sentences collide nowhere. - Set the doctrine down in five short sentences. There is exactly one God. The Father is fully God. The Son is fully God. The Spirit is fully God. The three are not one another. - Now hold those five against the test (P1). Where is the same thing affirmed and then denied of the same subject in the same sense? Full deity is affirmed of each person and denied of none. Distinctness is affirmed of each pair and denied of none. The number of Gods is given once and never taken back. - Compare the last four with a set nobody finds puzzling: Peter is human, John is human, Peter is not John. Same logical form, no strain anywhere. What Peter and John have no counterpart to is the first sentence, the one that gives the number. That is where a serious charge presses. (2) The identity reading is what generates the collision. - Take "the Father is God" and "the Son is God" as equations and the trouble arrives at once, because the Father turns out to be the Son. Take the same two sentences as predications and there is simply nothing to derive. - That explains something people notice without quite being able to name it. The contradiction is oddly hard to write down. Try it on paper and watch how much has to be assumed first. - The writers never granted that step (P4), so whoever takes it has supplied it himself. (3) A second route to the contradiction runs through the count. - No equation is needed for this one, which is what makes it the serious form of the charge. There is exactly one God. Three distinct persons are each God. If being God is being one of the divine beings there are, the total has gone from one to three inside two sentences. - Everything turns on whether "God" keeps one steady sense across those two lines: a counting word in the first, the very same counting word in the second. That is the second burden any charge of contradiction carries (P1, P2), and it has not been paid. (4) The doctrine says one what and three whos. - Somebody knocks at your front door. "What is out there?" gets "a human being." "Who is out there?" gets a name. Two questions, two kinds of answer, and nobody ever confuses them. - A being is what something is. A person is who someone is. The doctrine says there is one what and three whos, and it has said so from the start. - So the objection counts up the whos and announces the total as a number of whats. "Is fully divine" no more counts divine beings than "is feline" counts cats, and a house with one cat in it holds a great many feline things. (5) Defeating the contradiction charge is not the same as proving the doctrine. - The charge of formal inconsistency fails on both routes, and both need the same move: that "is God," said of a person, either names the one God or adds one to the count of Gods. That is a real result, and it is a narrow one. - It does not show the doctrine is true. Nor does it explain how one being lives as three persons, which is a genuine debt and a different one (P5). - Deductive premises are links in a chain, so if every link holds the conclusion cannot slip out. Each link only has to be more plausible than its denial, which is a lower bar than certainty and the right one. Therefore, the sentences the doctrine is built from can all be true together, and no one has yet derived a contradiction from them.

(P5) Consistency and explanation are different achievements. + Showing that a set of claims can all be true is one job. Showing how they are true is another, and the second is harder. (1) Serious knowledge often runs for decades on consistency alone. - Aspirin went on sale in 1899, and physicians handed it out for seventy years with no idea what it was doing inside the body. The mechanism was finally worked out in 1971. Nobody spent those seventy years calling the pills incoherent, and nobody stopped prescribing them. - Consistency is the lower bar of the two, and it happens to be the bar a charge of contradiction aims at. Clearing it settles that question and leaves the harder one exactly where it was. (2) The doctrine itself is only two sentences long. - There is exactly one God, and there are exactly three distinct persons properly called God. Those two claims are the doctrine. Everything else ever written on the subject is an attempt to say how they hold together. - A model is a proposal about how something works, offered to show that the claims can fit together rather than as revealed truth. • Physicists once pictured the atom as a miniature solar system, with electrons orbiting a nucleus the way planets orbit the sun. That picture was a model: a way of showing how the known facts could hang together, not a photograph of the thing itself. A model of the Trinity is somebody's account of how one divine being lives as three persons, offered in the same spirit. - Several serious models are on offer. They disagree with one another, and each of them pays a price somewhere. That is an honest state of affairs rather than an embarrassing one, and if a model fails tomorrow the two sentences do not fall with it. (3) Much of the classical difficulty comes from later tightening, not the biblical sentences. - The sharpest puzzles attach to constraints the church added afterward to guard the doctrine, of the kind gathered in the summary known as the Athanasian Creed: each person wholly God, no person the same as another, and yet not three Gods but one. - Those constraints were guarding something worth guarding. They protect the full deity of each person, and they refuse to let anyone imagine God assembled out of parts. Creeds are honored witnesses, and they earned their standing in hard fights. - What they are not is the starting point. A summary answers to the text it summarizes, and where a later formulation would make the doctrine incoherent, the sentences it was written to protect are the ones that govern. Therefore, the doctrine can be free of contradiction while the work of explaining how God is three in one goes on.

(C2) Therefore, the Trinity as Scripture states it needs no appeal to mystery and no revision of logic. + (1) The retreat to mystery costs more than it saves. - Christians sometimes meet the contradiction charge by saying the Trinity is above logic. That answer grants the charge and then asks the objector to be content anyway, and no thinking person should be. - There is genuine mystery in God, and Scripture insists on it: "his understanding is unsearchable" (Isaiah 40:28). Mystery means there is more to God than we can take in. It has never meant less than we can say without contradicting ourselves. - A doctrine that cannot be stated without collapsing is not deep. It is empty, and nobody should be asked to hold an empty doctrine out of loyalty. (2) The proposed repairs to logic are unnecessary too. - Two sophisticated rescues accept the identity reading and then revise something else so that the doctrine can survive it. Both come from serious philosophers, and both are expensive. - Relative identity holds that sameness is always sameness of some kind, so that "the same" never stands on its own. Think of a library that owns two copies of one novel. Same work, different volumes, and the question "are they the same?" cannot be answered until somebody supplies the missing word: the same what? On this proposal the persons are the same God without being the same person, and standard logic is rewritten to allow it. - Numerical sameness without identity takes a different road. The persons stand to the divine essence, meaning what it is to be God, roughly as a statue stands to the marble it is made from: one material thing, and still not simply one thing (P2). That one leaves logic alone and revises metaphysics instead, metaphysics being the philosopher's account of what things fundamentally are. - Whether either proposal succeeds is worth arguing on its own terms, and that argument can wait, because the bill may never come due. If the identity reading was never forced on anyone in the first place, a doctrine should not be pinned to the solution of a problem it does not have. (3) Stated plainly, the doctrine is not even puzzling at first look. - There is exactly one God, and there are exactly three distinct persons properly called God. Read the way the New Testament writers themselves read them, those two sentences generate nothing that needs rescuing. - Philosophers have a phrase for that. Prima facie, Latin for "at first look," the doctrine is unproblematic. The contradiction has to be manufactured, and manufacturing it takes an assumption the texts refuse to supply. - That is a stronger claim than mystery, and a calmer one than paradox. (4) What would defeat this. - Produce two sentences drawn from the doctrine, with their key words used in one steady sense throughout, where the same thing is affirmed and denied of the same subject. The whole case would be finished on the spot. - Show that the New Testament writers did draw the inference identity licenses, or did write "God is the Son," or did handle these statements as equations anywhere, and (P4) fails. - Show that "is God," in those writers' own usage, counts divine beings, and the second route to the contradiction opens whether or not anything is read as an equation (C1). Therefore, the doctrine can be stated in its own words, held without embarrassment, and defended without either an appeal to mystery or a rewriting of the rules.