Same Person, Different Name: How Truth Became Falsehood

The English draft matches the Korean source accurately with no meaning distortions, omissions, number mismatches, or structural issues.

Opening

Reader, in 16th-century Venice there lived a painter named Giorgione. His real name was Giorgio Barbarelli. “Giorgione” wasn’t his name — it was a nickname. It means “Big Giorgio.” He earned it because he was a large man.

So the following statements hold:

• Giorgione was called that because of his size. → True
• Barbarelli was called that because of his size. → False

Same person. But swap out one name, and truth turns into falsehood. Something feels off here, but pinning down exactly what’s wrong is trickier than it looks.

Giorgione’s Castelfranco Madonna, painted in 1505

In 1971, MIT philosopher Richard Cartwright supplied the answer. Let me give you the conclusion up front. Two things being identical, and two things being freely interchangeable in a sentence, are different principles — and the first does not guarantee the second. I think this 55-year-old argument describes, with remarkable precision, the structure of the substitution debates we have every single day.

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What We Thought Was One Principle Was Actually Two

There’s something usually called Leibniz’s Law¹. But under that single name, two different statements have been getting mixed together.

The first is the principle of identity. If x and y are the same thing, then whatever property x has, y has too. This is a claim about the world.

The second is the principle of substitutability. If x and y are identical, then in any sentence you can swap one for the other without changing its truth value. This is a claim about language.

Most people treat these two as saying the same thing, because they assume language simply transcribes the world as it is. But the Giorgione sentence shows that the second principle is simply wrong. A single counterexample is enough to bring a principle down, and we just saw one.

So does the first principle collapse along with it? For that to happen, there would need to be some property that Giorgione actually has but Barbarelli actually lacks. What could that be?

Maybe “being called that because of his size”? This is where it gets stuck. What “that” refers to isn’t fixed outside the sentence. Whether it means “called Giorgione” or “called Barbarelli” depends on which name has been plugged into the sentence. With nothing in front of it, “that” points to nothing at all.

This is exactly the point Cartwright identified. The problem wasn’t the person — it was the sentence. That sentence wasn’t talking about a single person alone. It was simultaneously talking about the name used to refer to that person. A name wasn’t a sticker you could peel off and reattach — it was a working part of the sentence itself.

So the fact that substitution breaks down doesn’t mean the two turn out to be different people. It only means that slot in the sentence wasn’t a slot reserved for people alone.

You don’t need to look far for this. Just think of the signature line on a contract.

• The contract was signed by the CEO.
• The contract was signed by Minsu Kim.

Even if Minsu Kim is the company’s CEO, the two sentences aren’t the same sentence. In the first, it’s the company that’s bound; in the second, it’s the individual. This is exactly why legal teams are so touchy about how a title is written on a signature line. Even when the person is identical, which name occupies that slot changes what takes legal effect.

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Pluto Proved the Argument for Us

Cartwright’s second example is even more entertaining.

• 9 is necessarily greater than 7. → True
• The number of planets is necessarily greater than 7. → False

As of 1971, when the paper was written, there were 9 planets. 9 and the number of planets were one and the same. And yet only one of these statements is true.

The reason lies in the word “necessarily”². That 9 is greater than 7 would be true no matter how the world happened to turn out. Whether there are 9 planets, though, is just a matter of chance. Had the solar system formed slightly differently, there might have been 6.

Cartwright’s diagnosis: the second sentence actually admits two readings.

Read the first way, it means the sentence “the number of planets is greater than 7” is itself necessarily true. That’s false. Read the second way, it means the number of planets is fixed at some particular value, and that value is necessarily greater than 7. Since that value is 9, this reading is true.

What looked like one sentence was, in fact, two sentences all along. The principle wasn’t broken — the words were simply hiding what they referred to. In philosophy, this distinction is called de re versus de dicto³.

Here comes the part I found most fascinating while reading this material. Cartwright notes, almost in passing, that 9 being the number of planets is simply a fact astronomy hands us. She uses it purely as background for the argument.

Then, 35 years later, in 2006, the International Astronomical Union reclassified Pluto as a dwarf planet, and the number of planets dropped to 8. The premise the paper had stood on turned out to be false — outside the paper itself.

But this doesn’t collapse the argument. It completes it. Cartwright’s whole point was that the expression “the number of planets” never referred to a specific value in the first place — it referred to a slot, and whatever value fills that slot can change at any time. The solar system went ahead and demonstrated, in physical reality, exactly what she had proven in words.

This distinction shows up in company documents every single day. Take a goal like “retain our top-ranked client.” Whether “top-ranked client” means that specific company currently ranked first, or whoever happens to be ranked first at any given moment, changes the entire strategy. If it’s the former, you should assign a dedicated team to that specific company. If it’s the latter, you should reallocate resources whenever the rankings shift. But the goal statement itself never tells you which. “Retain key talent” has the exact same problem.

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So the substitution debate keeps spinning its wheels

Now for the main argument.

These days, the substitution debate almost always runs on a single grammar: can AI do it as well as a human? Benchmark scores, accuracy rates, pass rates, percentage relative to humans. And beneath that sits an unstated premise: that once performance converges, substitution follows.

This is exactly the premise Cartwright dismantled 55 years ago. Even if sameness holds true, substitutability doesn’t follow from it.

Accepting this changes the diagnosis. When we try to substitute AI for a role and it doesn’t quite work, we usually conclude that performance still falls short and wait for the next model. But there’s another possibility: that the role was never one where only the output mattered, to begin with.

So which roles require the name attached, not just the output? Here are four criteria I’ve come to use in practice.

• Roles where accountability is recorded. Audit opinions, medical judgments, legal counsel, accounting sign-offs — work where who did it must remain on record, independent of the outcome.
• Roles where the relationship is part of the output. Long-term negotiation or counseling, where the fact that it’s this particular person is part of why the other side engages, and that fact is baked into the result.
• Roles where a person grows. This includes the repetitive tasks junior staff used to handle. Cut it today and nothing breaks today — but 5 years from now, no senior will have been made.
• Roles where someone must be asked “why” after the fact. Work that requires a person who can explain, retrospectively, why a judgment was made the way it was.

For roles that trip none of these four wires, substitution happens even at 80 percent performance — and it’s already happening. Conversely, for roles that do trip one of these wires, substitution doesn’t happen even at 100 percent performance. So what determines substitutability isn’t a performance threshold — it’s the nature of the role.

This isn’t abstract. It’s already hardened into institutional practice across multiple professions. A diagnosis carries the license number of the doctor who made it. An audit report bears the signature of the accountant in charge. A legal opinion carries the name of the attorney who wrote it. Why? Because someone needs to be held accountable when the judgment turns out wrong. Here, the name isn’t decoration that dresses up the output — it’s the condition that gives the output its force.

That’s why, in these roles, no matter how good the tools get, the structure doesn’t easily change. What actually happens isn’t substitution but reassignment: the machine writes the draft, the human signs it. On the surface it looks like the person is still there, but what that person does has shifted — from making to verifying. And this shift barely shows up on an org chart or in a performance metric. I think a large part of the confusion many organizations are experiencing right now comes from exactly this. While everyone breathes easy thinking “we haven’t been replaced,” the content of the work has quietly changed underneath them.

We should also be honest about the flip side here. Many of the roles we believe “need a human name attached” may just be untested inertia. I’ve seen it many times — the claim that something must be face-to-face, must be handled by someone with seniority, must have a final human check, repeated with no real grounding behind it. Cartwright, too, both acknowledged genuine counterexamples to the substitution principle and dismantled the fake ones, one by one. She did both at the same time. I think that’s precisely what’s needed now: separating the roles that are truly irreplaceable from the ones that are simply familiar.

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Oswald’s Lens

Helping teams review AI adoption means reading a lot of proposals and internal memos. Almost all of them contain one table without exception: the performance comparison table. Accuracy, processing time, cost per case, percentage versus human performance.

And almost every time, there’s one cell left blank. Whose name does this output go out under.

I don’t think that blank cell is a mere documentation oversight. It means the organization understands that spot as a place where only outputs come out. So when adoption doesn’t go as smoothly as expected, the first sentence that comes out in the meeting room is almost always the same: that the model still seems weak.

That diagnosis is half right. The other half is wrong. If that position was originally one where a name got attached too, the same problem will resurface in the same spot even if the model gets twice as good. This isn’t a problem you solve by boosting performance — it’s one you solve by redesigning where accountability and sign-off sit.

So lately, at the start of a review, I ask a different question. Instead of asking whether this can be replaced by AI, I first ask whose name is attached to this work’s output and why that name is necessary. If the answer comes immediately, it’s a position with fairly high replaceability. If the answer stalls, or ends with “that’s just how we’ve always done it,” that’s less a signal about replacement and more a signal that it’s time to reexamine the position itself.

For reference, I write a weekly newsletter that cross-analyzes technology, economics, and the humanities. Work like today’s — holding up an old paper against a current problem — is something I do often.

Closing

Let me sum up.

First, the principle that two things are identical and the principle that they’re interchangeable are different principles. Giorgione and Barbarelli are the same person, yet they can’t substitute for each other within a sentence.

Second, substitution breaks down not because the referent is different, but because the sentence is doing more than pointing at the referent — it’s also invoking the name.

Third, the test for replaceability isn’t some performance percentage. It’s whether the slot in question only needs the output, or whether it needs the name attached too.

I’d like to suggest one exercise for this week. Pick something you’re currently responsible for, and write two lines: whose name goes on the output, and why that name is necessary. If those two lines come easily, a substantial part of that task is already handoff-ready. If you struggle to write them, it’s probably not because the task can’t be handed off — it’s more likely that you’ve simply never worked it out before.

Reader, is there work of yours where, even if the output turns out identical, it still has to carry your own name? What is it, and why do you think that’s the case? Let me know in the comments. If enough examples come in, I’ll use the next issue to sort “work that needs a name” from “work that doesn’t,” role by role.

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💬 If there’s work where the output would be the same but it still has to carry your name, tell me in the comments — I’ll fold it into the next issue. 📨 If you have a colleague weighing whether to adopt AI, please pass this along.

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References & Further Reading

Primary sources

• Cartwright, Richard, “Identity and Substitutivity”, in Milton K. Munitz (ed.), Identity and Individuation, New York University Press, 1971, pp. 119-133. Link ··· This is the backbone of today’s piece. The Giorgione argument runs pp. 122–125, and the number-of-planets argument runs pp. 126–131. If the notation feels like a lot, just read the three pages starting at p. 122 — that alone gets you the core of it.
• Kripke, Saul, “Identity and Necessity”, in the same volume, pp. 135-164. ··· This is the chapter right after Cartwright’s. It tackles the exact same problem from the opposite direction. Read the two side by side and you can feel just how hot this debate ran in the early 1970s.
• Quine, W. V. O., From a Logical Point of View, 2nd ed., Harper and Row, 1963, p. 139. ··· The standard statement of the substitution principle that Cartwright takes issue with appears on this page. It was Quine, too, who first pulled the Giorgione case into the center of the debate.

Background

• Frege, Gottlob, “Über Sinn und Bedeutung”, Zeitschrift für Philosophie und philosophische Kritik, vol. 100, 1892, pp. 25-50. ··· This is where the debate begins: why do different names for the same object produce different sentences? The story of the Morning Star and the Evening Star — both names for Venus — comes from here.
• MIT Department of Philosophy, “Richard Cartwright”. Link ··· A full list of the author’s works. If you enjoyed this piece, his 1979 paper “Indiscernibility Principles” is a great place to go next.

Recommended past issues

• The People Who Turn Off Their 20-Watt Brains ··· The point of this piece is that machines beat the human brain not on performance, but on replicability. Worth reading alongside today’s discussion of “position.”
• What the Luddites Smashed Wasn’t the Machine ··· An analysis of how technology doesn’t eliminate labor so much as redistribute it. It shows how the “position that gets a name,” discussed in today’s piece, disappears in the course of that redistribution.

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The author is Oswarld (Kwangseob Ahn). Current roles: Adjunct Professor at Sejong University, Strategy Consultant at INLEVEL9. Career, research, books, and recent work are kept current on the About page. Latest · July 2026: HEMA-2: A Consolidation-Aware Tri-Memory Architecture with Multi-Channel Scheduling for Lifelong Conversational AI.

📝 Glossary

Footnotes

1. Leibniz’s Law: The principle that identical things are indiscernible from one another. If two objects are truly identical, neither can have a property the other lacks — but the core of today’s piece is that the version of this principle applied to words and the version applied to the world turn out to be two different things. ↩

2. Necessarily: Meaning that no matter how the world had turned out, this would have had to be true regardless. That’s different from simply being true right now. It’s true that Seoul is clear today, but that’s not necessary; that 3 plus 4 equals 7, on the other hand, is necessary. ↩

3. De re and de dicto: The distinction between reading a sentence as being about an object versus being about the sentence itself. Read “the number of planets is necessarily greater than 7” as a claim about a property of that number itself, and it’s true; read it as a claim that the sentence itself must be true, and it’s false. ↩