Questioning Materialism with Gideon Rosen: Part 2

May 16 2020

The previous issue of NZN featured Part I of my conversation with Princeton philosopher Gideon Rosen, in which we pondered this question: What does it mean to call yourself a “materialist” or “physicalist,” given that modern physics makes it hard to think of the world as consisting ultimately of solid particles or solid anything else. The difficulty of defining these labels leads to another question: Might they be a way of signaling not what you believe about reality but what you don’t believe—namely that you don’t believe the universe has a purpose (a “telos”) or comes with built-in moral truths? That’s where we pick up the conversation, which eventually leads to such topics as whether we live in a simulation, how we would know if we did, and whether the directionality of evolution (its tendency to lead to more complex and intelligent structures) could be evidence of a larger purpose unfolding on Earth. 

ROBERT WRIGHT: I wanted to touch on teleology. I think you said [once] that [“physicalist”] is almost like an identifier, a way of saying "I'm not a moral realist,” and “I'm not teleological," meaning, “I don't believe there's purpose in the world, certainly [not] a larger purpose.” Am I misremembering, or would you have said something like that? 

GIDEON ROSEN: Yeah, I do think that's part of it.

I mean, a whole bunch of things emerged together at the beginning of the 17th century with the scientific revolution. One was the rise of mechanistic physics as a fundamental theory of reality. Another—and these were not exactly the same thing—was the rejection of teleology in nature, the idea that the apt description of nature is in terms of the purposes of things, the functions of things, or the goods that are to be realized by physical processes. Those two things—the rejection of teleology and the rise of mechanistic physics—happened at the same time, with many of the same people involved… 

By the time the scientific revolution was mature, to be a hardheaded, scientifically-minded philosopher or theorist was to hold that fundamental physics involves mathematical properties of extended things spread out in space and time, and not moral properties. Not functions, not purposes, nothing like that. And not, by the way, anything outside of nature that might have endowed physical things with that kind of purpose, like God. 

So if you're a materialist or a physicalist now, you reject fundamental teleology and you also reject the supernatural...

It seems to me that one problem with that worldview is … the fact that we speak of a clock as having a purpose. 

It is a purely physical system. So certainly you can imagine ... a physical system that has a purpose, but we don't have to think of the purpose as residing in the system... We can think of the purpose as almost having to do with the nature of its historical development...

Now, I understand that you could ... say, okay, the universe could have a purpose in that sense, but we just don't think that there was some kind of deistic God that imparted [it]. As a matter of belief, I can see that. 

Although I would say that I think one current in thought that might lend... legitimacy to the view of this kind of purpose in the universe is all this stuff about living in a simulation, right? There are serious philosophers (plus Elon Musk, for what that's worth) who say: “Hey, we may be living in a simulation.” 

And that seems logically possible to me… And if that's the case, then it's an example of something where a system that looks to us like a physical system—functioning regularly, in accordance with laws—clearly does have a purpose that was imparted. Right?

Right. So there are two models for how something gets a purpose. 

One is the model of the artifact. 

The clock is made by a clockmaker. He's got a certain goal in mind, and if he achieves that goal with the clock to some extent, then it's the function of the clock, the purpose of the clock to, you know, tell the time. 

In the version of the simulation hypothesis that you were describing, all of the physical reality as we know it could be an artifact in that sense. That's what a version of that hypothesis says. 

It's a funny sort of artifact. The simulation view is that what the simulators did was made a computer or some device like that—that was a physical device of more or less the sort that we know about—and by running an extremely complicated program, the simulation device conjured into existence an image [of] simulated things. 

Now, when you run a computer simulation of a forest fire, to use one of Searle’s old examples, you're saying you want to know how forest fires work, so you write a computer program, which has elements that correspond to elements of the fire, and laws that correspond to the laws by which fires evolve, and so on. You run the program, you get information about how some fire might evolve. 

As we normally think, running that program doesn't conjure a fire into existence. There is no fire there at all. The program is just a false representation, it's a fiction. Nothing corresponds to it. 

What the proponents of simulation think is that when the simulation gets good enough and complicated enough, by simulating a world of people like you and me sitting in front of computers talking to one another, you somehow conjure into existence things that really are like that. 

So it's not as if there is no you, there is no me, there is no microphone—all of those things are, in some sense, part of the world, according to the simulation theorist—it's just that they are images produced by an underlying complex representational process. 

That's really weird

I agree that, if we can make sense of the idea of a computational process conjuring objects into existence, then it is a slightly crazy, but not utterly crazy speculation that we and the objects we know about are like that. 

This brings us back to idealism in the sense that all we can say for sure is that, to us, this seems like real fire. I mean, of course it does. We're the ones who labeled it “fire.”

I mean, ultimately, you're back to this very challenging question of what is subjective experience, why is it here, what's its relationship to reality... But I guess one thing I'd say is, to me, the more you think about materialism and all this stuff, the more you realize that, not only for all we know is that the case—that there's some computational machine generating these things that give us these impressions—but what is the practical difference between that and anything else we could say from our point of view?

Yeah. I mean… While we're on this slightly wild stuff: it's not as if we couldn't start getting evidence for some version of the simulation hypothesis, or the dream hypothesis...

If you started to detect intimations that there was a kind of creative intelligence behind the unfolding course of events that you couldn't find in the unfolding course of events—you know, the kinds of coincidences... 

I mean, someone could just sort of peel back the curtain and start saying, "You can't see me, but you can hear me. And I'm telling you, I wrote the program that you are a part of." That kind of thing, I guess, could happen—and you'd think you were losing your mind.

That is what we say about people who say things like that, yes. That they are losing their mind. 

But you can also start getting subtler, more interesting intimations—like the intimations that you get in dreams—that there's more going on than could be going on if the only intelligences in reality were the intelligences that we see.


You know, I'm a pretty well-rounded sort of guy, but I have time for the idea that that sort of thing is not that remote from actual experience, and if that started happening, all bets are off as to what the possibilities are for the source of that kind of meaning and experience. 

Could be "a geek sitting at some computer terminal in another reality simulating a world like ours." Could be something funkier than that...

I once was talking about the dream scenario with one of my daughters, and I said, “It just seems like, what are the chances that I'd be this lucky?”

I'm living at this fascinating time when the world is kind of coming together, there's all this knowledge out there, I'm privileged to be in this particular place, I get to do this, I get to do that, and think about these things and blah, blah, blah. I'm not one of the many other people that had been born in the dark ages, people who have no advantages and opportunities and no education...

And she said, "Well, yeah. But if you were one of these people, you wouldn't be asking this question." 

Now, was that an effective dismissal in your view? “If you didn't have the privileged position, you wouldn't be entertaining this question.” It's a lot like the anthropic principle, right? 

Yeah. I do think that's sort of effective.

Oh. I'm sorry to hear that. It's bad for both of us. You could make the same argument... 

Yeah. I mean, it's not an antidote to a related thought. 

There's the "How come I'm so lucky to be living at a moment when the possibility of this kind of coming to self-consciousness of the universe is possible?" Because that's what's happening over the course of relatively recent human history in this ridiculously small corner of the universe: people who are bits of the universe are in a position to think about the universe as a whole and to frame non-crazy, intelligent hypotheses about it. So the universe has come to, in this highly provisional way, understand itself just recently in cosmic time. 

I'm not sure how much mileage you get out of the question "How come we're so lucky to be living now?" 

But there is the question "Why did that happen at all?"

There you go... There are just aspects of the unfolding of life that are so amazing that they raise questions. You know, it does seem to be a kind of directional movement toward awareness of the universe. Some evolutionist said that evolution is the universe of becoming aware of itself. 

If you told some alien: Look, see, this is a system. Sure, it starts out with two replicating strands of information, but as you see it unfold, you can see, actually, [that] it's an algorithm for the universe coming to understand itself. They'd go: Ah, that seems like a pretty good algorithm. You know? 

That's one thing I mean—that's amazing. 

I agree that that's amazing. And unless you can just tell some general story about how, generically, if you start with the raw ingredients for natural selection, and things hum off for a long enough period of time, you're likely to get this kind of self-awareness—if that's not a generic feature of the evolutionary processes, then the fact that we have one of the special-case evolutionary processes that spat out that kind of self awareness is a fact that, as it's sometimes put, cries out for explanation.

Not every amazing fact needs an explanation. Sometimes things just happen and we can live with the idea that there's no story about why. But that's a pretty amazing fact. 

See, I would have taken it in the other direction: that natural selection, barring catastrophe, was likely to get—eventually, given long enough—to intelligent life. And there's some biologists who agree. 

And I would say that's the reason to think that the original self-replicating DNA is kind of like the seed of a flower or the egg for an organism, in the sense that the rest is a natural unfolding.

And when you see something like that, you go, wait a second, this demands a special explanation. With animals, the special explanation is natural selection. I'm saying, what is the explanation for natural selection itself? 

And I'm not saying that, if you had that explanation, you'd have the ultimate explanation. That might just push the question back one turtle, so to speak; it’s turtles all the way down.

But it's interesting that you can take it in either direction. You're saying, weren't we lucky, this is amazing luck—and I guess somebody could throw the anthropic principle objections at you in reply...

That version of the anthropic argument is lousy…

Oh, is it?

It seems to me. If it's antecedently unlikely that you'll get conscious things, and you ask the question “So why do we get them?”, and someone says “Ah, if you hadn't gotten them, you wouldn't be asking this question”—that does nothing at all to demystify the fact that we did get the amazing, unlikely outcome. I don't like that version of the anthropic argument at all. 

Ok… Just quickly: is the teleology question, in your mind, inherently related to the moral realism question?

It's sometimes hard for me to imagine, what does it mean to say that moral truths are in some sense out there, that they're in some sense real. Maybe in the simulation scenario you could say, "Well, if the programmer set up the game such that to survive humankind has to develop these moral ideas”—which I actually think may be the case—would that be a form of moral realism, because they were instantiated in the system as truths that must be arrived at?..

Natural teleology—the kind of teleology that emerges in, say, ordinary evolution, where you get "the function of the heart is to pump blood because that's what heart was selected for"—that kind of teleology has no normative force. The fact that it's the function of this or that to do this or that tells nothing at all about how we ought to behave with respect to it...

Take some impulse to sexual violence in men—which may, if the evolutionary psychologists are right, be real and exist as a result of some evolutionary whatnot—the fact that it's there and it has an evolutionary purpose just tells nothing at all about how we ought to act.


So, the kinds of moral features that are of interest to the moralist couldn't emerge all by themselves from that kind of natural teleology. So, if you're a real moral realist, you should think there are moral constraints on what we ought to do, how it would be good to act and so on that aren't grounded in that kind of function or purpose. 

I'm not sure they're grounded in functions or purposes at all. I think they're grounded in values. That is, things that are things that matter, things that are worth promoting, things that are worth doing.  

Illustration by Nikita Petrov.

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