How Can One Thing Be in Many Places at Once? Walter Burley and the Puzzle of Universals

You’re looking at a lemon. It’s yellow, sour, roundish. You take a bite. Your friend takes a bite from a different lemon. It’s also yellow, sour, roundish. Now here’s a strange question: Are they yellow in exactly the same way? Is the yellowness in your lemon the same yellowness as the yellowness in your friend’s lemon?

Most people would say no. Your lemon’s yellowness is in your lemon, and their lemon’s yellowness is in their lemon. Two different yellownesses, each in its own place. Simple enough.

But then think about the word “yellow.” When you say “this lemon is yellow” and “that lemon is yellow,” you’re using the same word. What makes that word work for both lemons? What is it that lemons share, if not the same yellowness?

This is the puzzle of universals—one of the oldest, weirdest problems in philosophy. And a 14th-century English thinker named Walter Burley spent his whole career trying to solve it, changing his mind radically in the process.

Here’s why this matters beyond just lemons. Think about all the things in the world. Every human, every cat, every rock, every red thing. When you say “Socrates is a human” and “Plato is a human,” you’re saying something true about both of them. But what makes it true?

One answer: There’s a real thing—“humanity”—that exists in both Socrates and Plato. It’s the same humanity in both of them. They share it. This is called realism about universals.

Another answer: There’s no such thing as “humanity” floating around. There’s just Socrates, and Plato, and they happen to be similar in certain ways. We group them under the label “human” because our minds find it useful. This is called nominalism (from the Latin word for “name”).

Both answers have problems. If universals are real, then one thing (humanity) is in many places at once—in Socrates and in Plato. How can one thing be in two places? That seems impossible. But if universals aren’t real, then what makes the word “human” mean anything at all? Why doesn’t it work just as well for a cat?

Burley started out as a realist, but not a simple one. He tried to find a middle path.

Burley’s First Answer: Universals as Parts of Things (1300–1324)

In his early career, Burley held a view that many philosophers of his time shared. He thought that universals—like humanity, yellowness, or roundness—actually exist in the world. They’re real. But they don’t exist separately from the things that have them.

Think of it this way: If you have a chocolate chip cookie, the chocolate chips are real. But they don’t exist apart from the cookie. You can’t have the chips without the cookie, and you can’t have the cookie without chips—they’re one thing, even though you can think about them separately.

For Burley, this was the relationship between universals and particular things. Humanity exists in Socrates and in Plato. It’s not a separate thing floating around in heaven. It’s actually part of what makes Socrates Socrates and Plato Plato. And here’s the key move: Burley said that a universal’s existence is the existence of the individuals that have it. Humanity doesn’t have its own separate life—it lives through Socrates and Plato.

This solved one problem: universals weren’t weird ghost-entities hovering above the world. They were right here, in things. But it created another problem: if humanity is really in Socrates, and Socrates is a particular person, then doesn’t that make humanity particular too? If the universal is in the particular, how is it still universal—how can it be in many particulars at once?

Burley’s answer was slippery. He said that universals are “naturally suited” to be in many things. They’re not actually in many things at the same time in the same way—they’re in each individual, but they have the capacity to be in others. Humanity is fully present in Socrates, but it could also be in Plato. That capacity is what makes it universal.

Many philosophers found this unsatisfying. It seemed like trying to have your cake and eat it too.

The Challenge: Ockham’s Attack

Enter William of Ockham—a brilliant, younger philosopher who became Burley’s great rival. Ockham was a razor-sharp thinker (literally: “Ockham’s razor” is named after him, the principle that you shouldn’t multiply entities beyond necessity). And he had a devastating argument against Burley’s view.

Here’s the problem Ockham pointed out. If universals are really in their particulars, then:

Whatever is true of the particular must be true of the universal too—since they’re the same thing.
But Socrates is one person, and Plato is a different person. They can be in different places at the same time.
If humanity is really identical to Socrates, then humanity is in Athens.
If humanity is also really identical to Plato, then humanity is in Syracuse.
So humanity is in two places at once—which should be impossible for one thing.

Worse, if you could destroy Socrates, you’d also destroy humanity in him. But humanity is supposed to be universal, existing in many people. So destroying one person would destroy something that also exists in others. That makes no sense.

Ockham’s conclusion: universals aren’t real things at all. They’re just names we use to group similar individuals. There are only particular things—this lemon, that lemon, this human, that human. The word “yellow” applies to both lemons, but there’s no single yellowness that they share. They just happen to be similar.

This is a clean, elegant solution. But Burley thought it went too far.

Burley’s Second Answer: Radical Realism (After 1324)

Ockham’s arguments convinced Burley that his first view was wrong. But instead of giving up on universals, Burley went in the opposite direction. He became an even stronger realist.

In his later work, Burley argued that universals and particulars are really distinct from each other. They’re different things entirely. Humanity is not the same as Socrates or Plato—it’s a separate reality that exists in them, but isn’t identical to them.

Wait—doesn’t that mean humanity is a weird ghost-entity after all? Burley said no. Here’s how he tried to make it work.

Burley said that every particular thing—say, Socrates—is actually a collection of many different realities. There’s the individual form that makes Socrates this particular person (his soul, his matter). But there’s also the universal form—humanity—that makes him a human being. Humanity really exists in Socrates, but it’s not the same thing as Socrates. It’s more like a visitor living inside him.

How can humanity be in many places at once? Burley said that universals have a different kind of unity than particulars. A particular like Socrates has numerical unity—he’s one thing, in one place, at one time. But humanity has specific unity—it’s one kind of thing that can be present in many locations simultaneously. It’s like how the number 2 can be present in two apples and two oranges at the same time—the number itself isn’t split up; it’s fully present in both groups.

This is a radical idea. It means that the world contains things that can be in multiple places at once. That sounds weird, but Burley thought it was necessary to explain how language and thought work. If the word “human” means something real, there has to be a real thing it refers to. And that thing has to be common to all humans.

What About Sentences? Real Propositions

Burley didn’t just think about words like “human” or “yellow.” He also thought about whole sentences. What makes a sentence like “Socrates is human” true?

His answer was strange and beautiful. He said that true sentences correspond to real propositions—complex structures that exist in the world itself. When you say “Socrates is human,” there’s something in reality that matches that sentence: the actual state of affairs where Socrates and humanity are joined together.

Burley called these “propositions in reality” (propositiones in re). They’re not sentences written on paper or spoken aloud. They’re not even thoughts in your mind. They’re things—actual features of the world that make true sentences true.

Think of it like this: The world isn’t just a pile of separate objects. It’s structured. There are connections between things. Socrates being human is a real feature of the world, not just something we project onto it. That feature—Socrates-being-human—is what Burley called a real proposition.

This idea was controversial then and still is now. Some philosophers think it’s obvious that the world has this kind of structure. Others think Burley was confusing language with reality—projecting the structure of our sentences onto a world that doesn’t have that structure at all.

Why It Still Matters

You might be thinking: “Okay, this is interesting, but does it matter? What difference does it make whether universals are real or not?”

It matters more than you’d think. Here are three reasons:

First, the problem hasn’t gone away. Philosophers still argue about universals today. Every time you say “this is the same color as that” or “she has the same disease I had,” you’re relying on some idea of what “sameness” means. Do things genuinely share something, or do they just look similar? The question touches how we understand science (what makes two experiments test the “same” thing?), morality (what makes two situations “unfair” in the same way?), and even everyday reasoning.

Second, Burley’s struggle shows something about how thinking works. He started with one view, got convinced it was wrong, and then built a completely different system—but one that kept his core belief that reality is structured and intelligible. That’s what philosophers do. They don’t just pick a side and stick with it. They follow arguments where they lead, even if it means rethinking everything.

Third, the puzzle is genuinely weird. Can one thing be in many places at once? Most people say no. But language seems to require it. The tension between what seems logically possible and what seems required by our experience is exactly the kind of thing that philosophy thrives on. It’s not a problem that gets “solved” and filed away. It keeps coming back, in different forms, every time someone stops to think about what they’re really saying when they say “same.”

Where Burley Ended Up

Walter Burley died in 1344, probably in his late sixties. He never convinced most other philosophers to adopt his radical realism. Ockham’s view—that universals are just names—became more popular in the long run. But Burley’s work survived, and philosophers today still study it.

Why? Because Burley saw something that many people miss. If you say universals aren’t real, you still have to explain what makes words work. You have to explain why “human” applies to Socrates and Plato and not to a rock. Ockham had an answer (they’re similar), but similarity itself is a kind of universal. What makes two things similar? If you keep asking, you might end up back where Burley started.

The puzzle of universals is like a philosophical hydra: cut off one head, and two more grow back. Burley understood this. He made his peace with having a universe full of strange entities—universals that are really distinct from particulars, real propositions that are states of affairs in the world—because he thought the alternative (a world without real shared natures) made even less sense.

Whether he was right is still an open question.

Key Terms

Term	What it does in the debate
Universal	A feature (like “humanity” or “yellowness”) that can be present in many individual things at once
Particular	A single individual thing (like Socrates or this lemon) that exists in one place at one time
Realism	The view that universals actually exist in reality, not just in our minds
Nominalism	The view that universals are just names or labels we use to group similar individuals
Real proposition	An actual state of affairs in the world that makes a true sentence true
Moderate realism	The view that universals exist but are identical to their particulars (Burley’s first view)
Radical realism	The view that universals are really distinct from their particulars (Burley’s second view)

Key People

Walter Burley (1275–1344): An English philosopher who started as a moderate realist and later became a radical realist after being challenged by Ockham. He spent decades thinking about how language connects to reality.
William of Ockham (1287–1347): A younger philosopher who argued that universals are just names, not real things. His criticisms forced Burley to completely rethink his view.
Aristotle (384–322 BCE): The ancient Greek philosopher whose work on categories and universals shaped the whole debate. Both Burley and Ockham were trying to figure out what Aristotle really meant.

Things to Think About

If universals aren’t real, how do you explain why two different things can be the same color? Is “same” just a word we use, or does it point to something genuine in the world?
Burley said universals can be in many places at once. Is that any stranger than saying numbers exist? After all, the number 2 can be in two apples and two oranges at the same time. Are numbers like universals?
If you think universals are real, you have to decide whether they’re the same as their particulars or different from them. Both options seem to cause problems. Which set of problems seems easier to live with?
Think about a game you play. When you say “this game is fun” and “that game is fun,” what makes both statements true? Is there a real thing called “fun” that exists in both games? Or are they just similar in a way we call “fun”?

Where This Shows Up

Science: When scientists say two chemicals have the same property (like “flammable”), they’re relying on something like universals. What makes the property the same across different samples?
Law: Laws apply to categories of people, not just individuals. When a law says “no one may steal,” it assumes there’s something real that all stealing has in common. What is it?
Everyday language: Every time you use a word like “red,” “kind,” “fair,” or “game,” you’re assuming there’s something shared by all the things you apply it to. That assumption is exactly what Burley was trying to make sense of.
Computer science: When programmers define a “class” or “type” (like “Dog” or “Car”), they’re creating something like universals—categories that apply to many individual objects. The same philosophical puzzles show up in debates about how these categories relate to the individual things in a program.

The Problem: What Do Similar Things Share?