And now, the very technical and insane follow up to the last post.
WARNING: What follows will blow your mind. Yes, there are philosophers who believe these things. On Tuesdays and Thursdays, I’m one of them. To put it simply, if you’re standing in a circle with other metaphysicians confessing to your strangest philosophical commitment, this is stranger than thinking tables and/or people don’t exist.*
So that whole thing about how the storyline can define nonexistent possible objects and beings? Not everyone buys that.
Mostly, because it’s pretty implausible when you actually want to talk about things themselves, rather than narratives. Though it may work for fiction, it’s absolutely terrible for discussing what individual things are.
For instance, those unicorns we were discussing last time. Twilight Sparkle and the Scottish unicorn are both called unicorns, but do we know that’s what they both are? After all, how could we tell the difference between Twilight the lilac unicorn and the Scottish beast, which is really a menicorn,** as it has one more lobe on its thymus gland? While we know some necessary conditions for calling something a “unicorn,” like single-hornedness and equineity, we don’t have sufficient conditions—that is, things that fit only unicorns. For instance, Twilight Sparkle can use magic, but probably has no interest in laying her head in a virgin’s lap; that tapestry unicorn probably wants nothing more than a convenient maiden to take a nap with, but wouldn’t know what magic was if hit with a spellbook. Yet both are still called “unicorns.”
Somehow, this ain’t right. You’d think something as big as “able to use magic” or “strangely attracted to virgins in order to serve as a Christ allegory” would be species-defining traits—but, if both are “unicorns,” it seems they either aren’t, or we’re using one term to talk about at least two different sorts of creatures.
As it turns out, the latter is probably true—we use the term “unicorn” to refer to all single-horned equines, naming them after some archetypical unicorn given to us by legends. As Saul Kripke describes it in Naming and Necessity, “naming after” does not imply that the original had any, much less all, of the traits the being named after them has, including identity; though there may have been a Turkish Christian bishop named Nicholas who was later canonized, the name “Saint Nick” or “Santa Claus” refers to someone/something entirely different who was named after the bishop.
Likewise the unicorns. If there is, in fact, to be some definition of “unicorn,” we’re going to need an actual unicorn; otherwise, there are just going to be too many metaphysical problems eluding any definition we can come up with.*** Unfortunately, we can’t find any unicorns; they don’t exist in this world, they never have exited, and, even if we cook one up in a lab and call it “unicorn,” we’re just naming after, rather than actually making a unicorn.
No, we’ll have to look somewhere else for a unicorn. Somewhere beyond this world.
This is where the crazy starts.
David K. Lewis was a brilliant man. One of the greatest philosophers of the late 20th century. Now, we start with the idea that all there is, at the bottom of it, is elementary bits of matter arranged in certain ways, and all else emerges from that. Basic materialism, right? Complex beings emerge from simpler beings, organs come from cells, humans from organs, consciousness from neurotransmitters, society from humans, civilization from societies, the rules for correctly governing one sort of behavior from the lower sorts, etc. The problem comes when you try to explain what could be, but just isn’t.
Now, on the face of it, there doesn’t seem to be a reason why unicorns couldn’t exist; it’s just that they don’t. However, if you’re going to explain everything in terms of matters of particular material fact, you’re going to need a material and factual unicorn somewhere. It can’t be in this world, so it has to be in another one. QED, no?
This is why people thought (and still think) Lewis was crazy. You start with a simple and obvious premise—atomistic materialism—and take it to its logical conclusion that just so happens to be absolutely absurd. Now, in fairness to Dave, lots of other philosophers hold the exact same sort of materialism he does, as well as the same reductionist theories of meaning and truth; they’re just not willing to bite the bullet and admit what their premises force them to be committed to.
But, if we’re going to talk about unicorns, they have to be beyond the world. Just to be clear, this isn’t some sort of multiverse—if there is a multiplicity of universes somehow related to or connected to this one, they’re all part of this possible world, not any other. No, there are a whole plurality—infinitely many, actually—of possible worlds, all just as real as this one, utterly unconnected to one another, except when we make reference to one.
Such as, in this case, a particular one containing unicorns that match up exactly with what we think “unicorn” means.
In this way, we can get around all the metaphysical problems inherent in not having a real, existing something to refer to. Instead, we have actual unicorns grazing on actual hillsides, or casing actual magical spells, in actual worlds. Sure, it’s a bit absurd, but see what it gets us? Common sense!
Like I said, every Tuesday and Thursday, I think this might actually have a shot of being right. It’s perfectly sensible, right up to the point you’re asked to actually believe it.
Perhaps it’s a cautionary tale against putting stock in common sense premises and good, ordinary logical deductions from them.