Functionalism about spatial properties

Functionalism about spatial properties says that what makes spatial properties be spatial is the kind of role they play in interaction with laws and regularities in the world. This allows the concept of spatial properties like shape or distance to be independent of the precise physics of the world. For instance, one might say that distance is a relation largely characterized by a correlation between itself and weakening causal interactions.

I find functionalism about spatial properties attractive, but it just occurred to me that if one is not careful, it might turn out that the virtual spatial relations in virtual worlds end up counting as real spatial relations.

Vagueness, artifacts and virtual reality

Suppose Wilhelmina spends most of her time in an extremely detailed virtual reality environment. Therein, she uses virtual tomahawks, virtual knitting needles and virtual laser rifles, and chats with various people, some of whom are virtually bald (in the sense of "virtually" in "virtual tomahawk") and some of whom aren't. She does not use the "virtual" and "virtually" qualifiers, however. She talks of fighting a non-bald enemy with a tomahawk, knitting a sweater for a bald friend and engraving a plaque with a laser rifle for the runner up in the Easter egg hunt who neither definitely bald nor definitely non-bald. She speaks all of these things very naturally, the way she would were the virtual reality not merely virtual, though if you ask her, she will tell you that fundamentally all that reality exists through its representation in a network of computers.

There are at least two lessons to be learned from this story.

Lesson one: We should not find implausible the idea that the full range of sophisticated discourse exhibits the kinds of vagueness that it does, but nonetheless there is no vagueness at the fundamental level. Wilhelmina's linguistic and non-linguistic interactions in the virtual world can, in principle, have all of the structural complexity of non-virtual interactions. She calls one denizen of her virtual world "bald" and another "non-bald", and she says that it is not definite either way whether her pet Ganymedan ice-worm has died yet or whether she has climbed two mountains today or one mountain with two peaks. Yet none of that threatens the non-vagueness at the fundamental level of the digital implementations (assuming that's in fact non-vague). I submit that the same is true in the non-virtual world, and in fact that the lack of vagueness at the fundamental level is a powerful way of judging what is not fundamental.

Lesson two: What do we want to say about the ontology of the objects in the virtual world? The following seem to me to be correct. The virtual artifacts are artifacts. While the virtual tomahawk isn't a tomahawk, it is, nonetheless, a tool. An artifact is something that is for use, and Wilhelmina does appropriately use the virtual tomohawk to achieve certain results. A virtual killing of a virtual wolverine is not a killing, but it can nonetheless be the achievement of a goal. Artifacts can be implemented in all sorts of ways. One could have a portion of a magnetic field as a box. The virtual tomahawk is then a tool (just as much as programmers quite properly talk of various computer programs like compilers and linkers as "tools"). The virtual tomahawk is a tool, and at least if it was designed by someone (say, Wilhelmina, out of virtual iron and a virtual stick), it is an artifact. But we do not, I think, want to say that the virtual tomahawk really exists. Therefore some artifacts do not really exist. But I do not think one can really make a further ontological distinction within artifacts, between those that really exist (maybe like tomahawks) and those that don't (maybe like virtual tomahawks and boxes made of portions of magnetic fields). So, it is plausible that no artifacts really exist.

Observe also a contrast with living things. While the virtual tomahawk is not a tomahawk, but is nonetheless a tool, the virtual wolverine is not only not a wolverine, but is not alive at all. Why? After all, maybe the simulation is very detailed and includes all of the relevant internal processes. I say that the reason we don't want to say that it's alive is that things that are alive really do exist, while the virtual wolverine does not.

Virtual reality and ontology

Consider a vorpal sword in a multiuser game. Does it exist? I think not. The computer simulates a sword, but there is no simulated sword.

Suppose you disagree and think there were such an object. The object then seems, prima facie, to be both a non-defective sword and an immaterial object unable to cut any chunk of matter. This seems to be a contradiction. To get out of the contradiction, you probably need to say that the vorpal sword is not a sword—it's a virtual sword. And it can virtually cut some virtual chunks of matter. For many positive material properties that a non-virtual sword would have to have, the virtual sword has a virtual counterpart. But not for all of them. While a real sword would have to either be made by a human smith or not made by a human smith, if the game designers failed to specify the sword's history, then it will neither be true that the sword was virtually(made by a human smith) nor that the sword was virtually(not made by a human smith). There is no violation of excluded middle here.

But there may, nonetheless, be some properties that the virtual sword shares with real swords. The virtual sword may be owned by Jane, who also owns a real sword. The virtual sword may be beautiful, just as a real sword. And, of course, on the view in question, just as the real sword has existence, so does the virtual one.

But now consider this puzzle about identity. Suppose two people playing the game have vorpal swords with exactly the same identities. They put them down in a box. They close the box. They shake the box. Then they each take a vorpal sword out of the box. Do they get their own swords back, or have they swapped them? Suppose the game designers failed to specify the physics of what happens in the box—that's, after all, always possible in the case of virtual reality (it may not be specified just how long the intestines of the dragon are, though it may be specified that it has intestines). There is no entity without identity. If the virtual swords were real, there would be a fact about whether they went to different owners or not. I suppose we could say that after the swap they each come to have the same future properties as the other: virtual sword A has the property of virtually being owned by Jim or by Susan but not both, and so does virtual sword B, and neither has the property of virtually being owned by Jim or of virtually being owned by Susan. Each sword has the property of virtually having different present properties from the other sword, but neither sword actually has any different present properties from the other, after the swap.

Now, you might think, and you would I think be right, that all this is absurd. You might think that while there virtually are vorpal swords there are no virtual vorpal swords. But why not? One reason is that there are puzzles about identity. But there equally are puzzles about the identity of real swords. Another reason, and perhaps a more compelling one, is that whether Jim has a vorpal sword might just be a matter of the value of a single bit in the attributes of Jim (probably more in a sophisticated game) along with context. But likewise a real sword seems to be just a matter of the positions of particles, or maybe just of values of a field. Social constitution goes into virtual reality. But likewise into artifactual reality. And so on.

Conversely, various reasons for believing in real swords apply to virtual ones. The real swords enter into explanations of phenomena. So do the virtual ones. ("Why did George lose the fight? Because his opponent wielded a vorpal sword.") The real swords are thought of and felt about as if they were real. So do the virtual ones after people have been playing the game long enough. The real ones are apparently perceived. So are the virtual ones.

What does this mean? I think this will push in one of two directions. One way is if one holds on to the intuition that something whose existence is "a matter of the properties of other things" does not count as a thing. Thus, the vorpal sword is constituted by bits in the owner's attributes along with context is not a thing. But neither is a real sword if it turns out that its existence is a matter of the properties of particles or fields. Then one will conclude that artifacts, as such, do not exist. Given the undeniability of our own existence, we will have to conclude that we are different in some important sense from swords and bicycles—our relation to the underlying physical world is different.

Alternately, one might conclude that virtual items exist. But where will one draw the line, then? Once one allows virtual items to exist, one will almost surely have to allow fictional items to exist. Sherlock Holmes will exist. Will his gall bladder? Where will one stop? This way lies mad ontological profligacy.