Fun Facts about the Human Body, Plus a Wild But Serious Idea

In the Wake of the Accidental War

The world is full of tiny things. I mean tiny, capital-‘T’ Tiny. Given just how small the small things are, the “things” we talk about and interact with, the ordinary objects of the macro-level world, contain unfathomable quantities of the tiny things.

Literally unfathomable. A human body, for example, contains something like 100 trillion cells. And a single cell contains, on average, something like 40 million protein molecules, which in turn can contain thousands of atoms. Even the atoms are made up of smaller bits. We not quite sure how far down it goes.

Just to be a bit more concrete, consider red blood cells. By some estimates, you have 25,000,000,000,000 of them. That’s not a typo: 25 trillion red blood cells. Red blood cells contain hemoglobin, the protein that does much of the heavy lifting of oxygen-delivery inside your body. Ever wondered how many hemoglobin molecules are in each red blood cell? The answer is 260…wait for it…million. No joke: there are 260,000,000 hemoglobin molecules in each red blood cell. (Don’t believe these estimates about the quantities of red blood cells and hemoglobin?) Oh by the way, a single hemoglobin molecule contains around 10,000 atoms. Put all this together—25 trillion red blood cells containing 260 million hemoglobin proteins per cell with 10 thousand atoms per hemoglobin molecule—that’s roughly 65,000,000,000,000,000,000,000,000 atoms just to constitute your body’s hemoglobin.

(I would bet good money that none of you know the English-y name of 6.5*10^25. I didn’t, that’s for sure. Looked it up, though. Its name is ‘65 septillion’.¹)

And remember, the atoms aren’t even the smallest bits!

Point is, your body is a constellation, a swarm, of a lot of fundamental bits.

And there’s more: swarms of the atoms can overlap. Think about the swarm of atoms that is your body. There are 65 septillion atom-swarms which contain all of the atoms in your body except for just one of the 65 septillion hemoglobin-constituting atoms. Each of these 65 septillion swarms is unique. They’re constituted by different bits. Oh, and if you think about the swarms that include every atom in your body minus exactly two of those 65 septillion hemoglobin-constituting atoms, you get another

\(6.5\times10^{25}\choose 2\)

swarms. That math-y thing is read, in case you care, “six point five times ten to the twenty-fifth choose two”. 65 septillion choose 2 is a very big number. I don’t know it’s proper English-y name, in part because I didn’t bother to actually to do the calculation, but in larger part because even if I had calculated I still wouldn’t know it’s name.²

Now think about the swarm of bits in that Trader Joe’s dark chocolate peanut butter cup that you have teetering on the brink of your maw, grasped between your vicious butter-cup-crushing mandibles. At some point in the near future, your body will begin to absorb the bits from the peanut butter cup. Where and when and how that happens needn’t detain us. But at that point, there will be a vast array of almost entirely overlapping swarms. Some of them include every bit that’s a part of your body plus only one bit of what had been that delicious, cocao-constituted conical frustum (Perhaps it’s on the cusp of being a body-bit, just beginning the process of digestive absorption.) There are also the swarms including two bits from the peanut butter cup. Or three.

Photo by James Wainscoat on Unsplash (cropped)

If you’re having trouble picturing all of this, consider the photo just above, which seems to me to contain an airborne, starling-constituted manatee. There’s that one starling near-ish the upper right corner that is maybe manatee-constituting, maybe not. Regardless, there’s a swarm—many really—which contains ol’ top-starboard Flappy McFlapFace. Another swarm—many really—doesn’t contain her. Maybe the few lazy tweeters you can just make out down in the trees are exiting the manatee. Maybe entering. Lots of blackbird swarms in Mr. Wainscoat’s photo. So many you can’t count them. Which one is the skybound mammalian blubber-fish? Is there only one? Who knows?

The atom-swarms in and around you are are even more, unfathomably more, numerous than the starling swarm in that photo. A murmuration of starlings can contain upwards of a million individual starlings. That’s less than four tenths of a percent of the number of hemoglobin proteins in a single red blood cell. But like the swarm of starlings relative to the flying manatee, the atom-swarms around you are almost entirely overlapping. Shaped roughly like your body. Involving heart-swarms and kidney-swarms and brain-swarms, of which there are likewise so very many. The body-swarms all are doing human-like things like grabbing more dark chocolate peanut butter cups to stuff inside your face cave.

Indeed, it’s not always obvious when some swarm of bits constitutes a human body. There are bits entering and exiting more or less all the time. And there are bits that are sorta part and sorta not. Think gut bacteria, or cancer.

You get the idea. Lots of swarms.

In all this, there is only one you.

But which swarm are you? Which is the swarm that your name picks out? Is there really any fact of the matter? In the world-as-universe, it’s difficult to understand how your body could be any more unified than the floating puffer puppy in that photo. And so it’s difficult to know which swarm you are, if you’re even only one.

This is what you might call the Puzzle of the Swarm. We’re return to this after a bit of a meander.

Katherine Hawley was not a household-name type philosopher. But she was an excellent philosopher, better than some of the household-name types. A long time member of the Philosophy Department at the University of St. Andrews, she was a Fellow of both the Royal Society of Edinburgh and the British Academy. Hawley’s was a serious mind. Unlike some academics, who so often pigeon-hole into extremely narrow areas on which they work for the whole of their careers, Hawley’s interests were wide-ranging. Toward the end of her life she was working on issues of trust and trustworthiness. But the beginnings of her distinguished but ever-too-short career—sadly, she passed away not long ago, too young, in April 2021—were devoted to a field I’ve written a word or a few hundred thousand about: metaphysics.

In How Things Persist (Oxford University Press, 2001), for example, Hawley is wrestling with how and under what conditions individual things can survive despite changes of various kinds. She’s working to articulate what metaphysicians call “persistence conditions”. This has been a puzzle for a while. Perhaps you’ve heard of the Ship of Theseus. The Ship of Theseus is made of wood, and over time individual planks rot and get replaced by new ones until, in the end, none of the original wood remains. The puzzle concerns how much of this sort of substitution the original ship can survive. At what point, in other words, do you have just a different ship?

The puzzle gets worse if you keep the old planks and at some point reconstitute a ship with them. Maybe you’re a Theseus fanboy yenning to play with his ship. Maybe you’re a museum curator. Maybe you want to build a history-based worldwide tourist destination, like that Ark thing in Kentucky. I could go on! Anyway, a ship built out of the original planks after they’ve slowly been replaced on the continuously seagoing ship creates a challenge: which ship is the Ship of Theseus? There’s only one, but two “swarms” of planks lay claim to title.

With a general account of persistence conditions, perhaps we could solve this problem. That’s what Hawley’s up to in How Things Persist.

If you think this is just a bit of esoteric whatever-whatever, I’ve got news for you. Questions about ownership depend on these sorts of persistence questions, since ownership is parasitic on identity. And, more personally, lots of folks think you’re just your body. And that your body is just a collection of cells or atoms or whatever. And that those cells or atoms change over time. Are you the same person as you were when you were ten? And if not, why do you still complain to your therapist about that one time your mom made you—you—do that thing?

The point is: the question about the planks of ships of reputed minotaur-slaying Athenian founders is merely an illustration. But the illustration is illustrating something that matters to our politics, our morality, even our very selves. No one actually cares whether Theseus’s ship survives. But people do care—you should care—whether your family, your people, your property, and you yourself survive.

Anyway, in the introduction to How Things Persist, Hawley lays some ground rules, and along the way says something that, to the uninitiated, is utterly and completely bonkers: persistence conditions may just be stipulated, decided by us, by our choices about how to use language.

Here are Hawley’s own words:

To think that we can define, decide, or stipulate persistence conditions [that is, the conditions under which something can remain the same while undergoing some sort of change] is to think that we can define, decide, or stipulate whether or not a certain object which exists right now also existed yesterday. Taken literally, this view attributes to us mystical, magical powers to affect the past, to create and destroy things by the mere power of thought, rather than through any physical manipulation, and for that reason I reject it, at least in so far as it applies to material objects. Yet this realism is an assumption that I will not attempt to justify; there is a rich and ancient debate about the ways in which mind may or may not play a role in constituting the world of material objects, and I will not engage with that debate here. Instead, I hereby advertise my assumption that we cannot in general alter facts about the persistence and existence of material objects, except by physically manipulating the world.

There is, however, a less radical way of spelling out the idea that the persistence conditions of material objects may be a matter of definition, decision, or stipulation. This is to suppose that it is at least partly a matter of definition, decision, or stipulation how we divide up the world into persisting objects, or which persisting things we choose to talk about. That’s to say, perhaps it is to some extent ‘up to us’ whether by ‘person’ we mean a kind of thing which begins to exist at conception, or one which begins to exist at some later moment.

You’re reading that right, folks: whether a zygote is a person may just be a question settled by how we choose to use the word ‘person’.

How could this be? Hawley continues, picking up the very next sentence:

To be interesting, this claim must not simply be that it is up to us what sense we attach to our words. It must also be that the world is densely populated, so that it is amenable to different classification systems, different ways of thinking about the world. If we can choose whether ‘person’ applies to objects which begin to exist at conception, or else to objects which begin to exist at some later date, then there must be objects of both sorts in the world.

Translation: There are human-like objects that begin at conception, and human-like objects that don’t. The mere existence of these objects—including the ones that begin at conception—isn’t the issue. The issue is which of these objects we decide to call ‘person’. Carrying on, again skipping nothing in Hawley’s text,

If persistence conditions are in part a matter of stipulation, and yet mind does not constitute the world, then material objects must be abundant: there are many ways in which we might have divided up the world into objects, and objects corresponding to those various schemes already exist. Are the objects abundant in this way? I believe that they are.

Here is the picture.

The world is a universe. It’s a swarm of small things bumping in the void. In the swarm are many mini-swarms. What makes a mini-swarm the swarm that it is, is simple: it’s got the same fundamental tiny bits. These mini-swarms are nothing more than collections or constellations of bits. Same bits, same swarm; different bits, different swarm. The world is “densely populated”, in Hawley’s terms, with such mini-swarms. So there a lot of swarms. One for each collection of fundamental bits.

Minds don’t make the swarms. They simply choose to name, to talk about, some of them rather than others. The dense population of swarms makes it possible for us to adopt “different classification systems”, to divide up the world in different ways without making mistakes about what’s really there. There’s so many swarms that no matter how we talk our words are bound to grab onto the world in a metaphysically adequate way!³

Ordinary objects, including you and me, are just swarms. And we’re surrounded by other swarms, metaphysically just like us, but that aren’t so ordinary. We’re no more real than these weird objects. Deep down, so far as the world is concerned, ordinary and non-ordinary are alike simply swarms.

And so we return to the Puzzle of the Swarm, which is in the background of this remarkable passage of Hawley’s. Her reaction, her solution to the puzzle is as elegant as it is flabbergasting: we give names to some swarms—perhaps it’s better to say we give names to some swarms of swarms—and not to others. There are many swarms, but only some get names. We don’t make the swarms, but we decide which ones are worth talking about. And we ourselves are just one among the unfathomably many swarms, lucky to have been named.

Remarkably, this picture is an assumption of Hawley’s book.⁴

I’m going to assert a couple things now. I hereby pledge to underwrite these assertions later, by describing how we got to a point where an imminent philosopher writing a book on the most respected academic press could assume something that sounds, on its face, so profoundly stupid. But for now, just bald-faced assertion:

There is a prominent, serious philosophical tradition whose inevitable conclusion is right here. That tradition is bound up with the Accidental War on Humanity. The solutions on offer to the puzzles that developed within this tradition are as yet unsolved, including the Puzzle of the Swarm. Solutions have been proposed. But they are almost certainly false. Regardless, to appreciate the trajectory of this tradition, you have to push into the question: what, exactly, are minds for? What are minds doing, and how do they do it. Major—and I mean major—shifts have occurred on these questions. And so it is to the mind we must turn.

1. U.S. English and British English disagree about the names of these big numbers. I’m speaking U.S. because ‘Murica.

2. Okay, so I did estimate: it’s somewhere a bit north of 2 sexdecillion (U.S.-speak). That’s a 2 with 51 zeroes after it. 51!

3. But can’t we speak falsely? Of course! It takes a while to understand how this could be so, and now isn’t the time to follow that rabbit trail, I’m afraid…

4. The argument of Hawley’s book is that we can likewise apply this sort of many-swarms-only-some-get-names idea to persistence, to when something can survive change.