Wednesday, October 31, 2012

Nietzsche's Eternal Recurrence, Scrambled Sideways

Nietzsche writes:

What, if some day or night a demon were to steal after you into your loneliest loneliness and say to you: "This life as you now live it and have lived it, you will have to live once more and innumerable times more; and there will be nothing new in it, but every pain and every joy, and every thought and sigh and everything unutterably small or great in your life will have to return to you, all in the same succession and sequence? -- even this spider and this moonlight between the trees, and even this moment and I myself. The eternal hourglass of existence is turned upside down again and again, and you with it, a speck of dust!"
Would you not throw yourself down and gnash your teeth and curse the demon who spoke thus? Or have you once experienced a tremendous moment when you would have answered him: "You are a god and never have I heard anything more divine." If this thought gained possession of you, it would change you as you are or perhaps crush you. The question in each and every thing, "Do you desire this once more and innumerable times more?" would lie upon your actions as the greatest weight. Or how well disposed would you have to become to yourself and to life to crave nothing more fervently than this ultimate eternal confirmation and seal? (Gay Science 341, Kaufmann trans.).

Unlike some readers of Nietzsche, I'm inclined to think Nietzsche intended his remarks about eternal recurrence not as a mere thought experiment but rather as a genuine cosmological possibility. His unpublished reflections on eternal recurrence suggest a view not unlike that of his contemporary, physicist Ludwig Boltzmann. In a universe of finite relevantly different combinatorial possibilities, infinite duration, and some means of avoiding permanent collapse into entropy, it is plausible to think that eventually the current configuration of the world will recur, not just once but infinitely often. And if one adds determinism to the picture (as most would have done in the 19th century), then once the current configuration recurs, the same subsequent states will follow. Voila, eternal recurrence.

Now update to the early 21st century by adding multiverse theory and randomness. What do we get? Eternal recurrence scrambled sideways! Sideways because the infinitely many duplicates of you need not exist only in your past and future (and in fact probably don't, assuming a finite or entropy-collapsing observable universe and universe-local spacetime) -- rather they exist "sideways", outside of our observable universe. And scrambled because rather than being destined always to play out the same, every finite possibility is played out, infinitely often.

So, on this view -- which is well within the range of the mainstream options in contemporary scientific cosmology -- there are infinitely many "Eric Schwitzgebel"s in infinitely many universes who have lived their lives identically to mine up to this minute. Given that there is a huge variety of highly improbable but finitely probable weird futures for these Eric Schwitzgebels, infinitely many Eric Schwitzgebels play out each of these weird outcomes. Infinitely many of my up-to-now counterparts decide to leave philosophy forever to pursue a hopeless career in football, infinitely many leap to death from the top of the tower, infinitely many spend the rest of the week stapling pages of Kant's first critique atop relevant passages of Hume's Treatise. And of course infinitely many also finish this blog post, in every possible way it might be finished.

How should I feel about these counterparts of mine, assuming such a cosmology is the correct one, as seems possible? They are oddly close to me, in a way, though universes distant. I can't quite find myself indifferent to them -- just as Nietzsche can't find himself indifferent to his future counterparts who must live out his every decision. Though it seems weird to say so, I find myself feeling sorry as I imagine their sufferings. I don't feel the heavy weight of Nietzsche's eternal recurrence, though. I'm not sure I would feel that weight even on Nietzsche's original assumptions, but definitely not now. Maybe instead there's a lightness: Even if I decide wrong, there will be infinitely many Erics who get it right! Conversely, there's an eeriness too: Infinitely many Erics bashed their cars headlong into that oncoming traffic.

Maybe I shouldn't take such reflections very seriously. The cosmology might not be correct. Even if it is correct, I'm the only Eric Schwitzgebel, UC Riverside philosopher, in this universe, and I really shouldn't care at all about what transpires in other universes, no matter how eerily similar. Should I? There are plenty of other people, right here on our own Earth, past and future, whom I should care about more, right? Because they're... well, why exactly? Because they're closer?

Wednesday, October 24, 2012

Group Minds on Ringworld

In the year 3000, let's suppose, humanity completes its greatest construction project ever: Ringworld, a habitable surface as wide as a planet but spanning an entire planetary orbit -- a ring around a neighboring star with 10,000,000,000,000 square kilometers of living space. A big place!

Earthly nations send colonists. Once on Ringworld, the colonists form independent nations, free of Earthly control. These nations grow and spread. For sociological reasons, let's suppose, Ringworld nations function best with populations near 100,000,000. Once a nation grows much larger than that, it tends either to fission or to stagnate. Now, what type of nation will be well represented on the surface of Ringworld after ten thousand years?

Although it could play out in various ways, the most straightforward answer seems to be: nations that grow fast, then fission, then repeatedly grow again and fission again. Mobility to unpopulated parts of Ringworld, away from competitors, might also be favored. Also, we might expect the most evolutionarily successful nations to have intergenerationally stable developmental resources -- that is, to be such that their fission products tend to develop the same traits that the fissioning parent nations had, i.e., the very traits that made those parents evolutionarily successful. Otherwise, after a few generations, those nations' fission-produced offspring nations will be outcompeted. We might further imagine that the most successful nations employ eugenics: Their governments select a range of DNA strands containing especially desirable traits, which then serve as the genetic basis of the next generation of their citizens; and the governments that do so with the best eye to maximizing their nations' eventual descendant nations, and that do so stably over the generations, are eventually the nations that are best represented on the Ringworld surface.

We might imagine, too, that as the Ringworld surface becomes more crowded, aggression starts to pay. In response, the competing nations develop protective physical borders, grown using nanotechnology and difficult to penetrate without permission. Nations might also strictly limit immigration as contrary to their eugenic plans. If nations are somewhat mobile -- and we might imagine that gravity (or centrifugal inertia) is light and fusion power plentiful -- they might best compete with each other by moving toward opportunities and away from threats, bringing their citizenry and physical defensive borders along with them. Eventually, these defensive borders might gain appendage-like functionality -- e.g., offensive weaponry and the ability to harvest minerals and sources of power. Once this happens, the majority of individual citizens might become largely sedentary, communicating via radio and microwave signals. And once sedentary, size-reduction might be selected for, to reduce the energetic costs of nation-scale movement; and transmission of essential nutrients between citizens might be achieved by purely mechanical means. Furthermore, once free of the demands of individual mobility and individual-level reproduction, citizens might start to specialize ever more narrowly in tasks that serve the reproductive interests of the nation -- or at least the nations whose citizens develop in that direction might in the long run outcompete the nations whose citizens do not.

Over time, as individual citizens shrink and become increasingly specialized, and as the membrane around the nation becomes more functional and more effectively protective of the interior, the overall physical structure of the nation might start to look increasingly like that of what we would call an individual organism that reproduces by fission.

Nations -- at least the evolutionarily most successful ones -- will presumably engage in social intercourse among each other, both cooperatively and competitively. Possibly, some of these nations will evolve so that no single individual citizen is responsible for between-nation communication but rather the communicative efforts arise in a complex way from the citizenry as a whole. If individual citizens become sufficiently small and specialized, and if they learn to communicate with each other non-linguistically (e.g., by direct brain-to-brain stimulation), then it might eventually become the case that no individual citizen can even understand the linguistic communications emitted by her own nation.

A million years passes, during which Earth loses communication with Ringworld. Social pressures on Ringworld favor increasingly sophisticated forms of communication between nations, including the emergence of nation-level art, poetry, song, history, and philosophy -- none of which is comprehensible to the individual citizens of the species of nation that eventually conquers the rest. After these million years, visitors from Earth arrive, and they decide that conscious experience is primarily to be found at the level of nations, not at the level of individual citizens.

Question: At what point in this process did the nations first have nation-level conscious experience?

Might it have been from the very beginning?

Wednesday, October 17, 2012

Do You have Infinitely Many Beliefs about the Number of Planets?

If you're like me, you believe that the solar system contains eight planets. (Stubborn Plutophiles may adjust accordingly.) You probably also believe that the solar system contains fewer than nine planets. And you probably believe that it contains more than just the four inner planets. Do you also believe that the solar system contains fewer than 14 planets? Fewer than 127? Fewer than 134,674.6 planets? That there are eight planet-like bodies within half a light year? That there are 2^3 planets within the gravitational well of the nearest large hydrogen-fusing body? That there are 1000(base 2) planets, or -i^2*e^0*sqrt(64) planets? That Shakespeare's estimate of the number of planets was probably too low? Presumably you can form these beliefs now, if you didn't already have them. The question, really, is whether you believed these things before thinking specifically about them.

Standard philosophical representationalist approaches to belief seem to fare poorly when faced with this question.

Here's a typical first-pass representationalist account of belief: To believe some proposition P (e.g., that the solar system has fewer than 9 planets) is to have stored somewhere in one's mind a language-like representation with the content P -- and to have it stored in such a way that the representation can be deployed for appropriate use in inference and practical reasoning. Now, one possibility, on such a view, is to say we have all the beliefs described above and thus that we have a vast number of stored representations with very similar content. But that doesn't seem very appealing. Another possibility seems more initially promising: Say that we really only have a few stored representations concerning the number of planets. Probably, then you didn't believe (until you thought about it just now) that there were fewer than 14 planets.

But there are two problems with this approach. First, although I certainly agree that it would be weird to say that you believe, before doing the relevant calculation, that there are -i^2*e^0*sqrt(64) planets, it seems weirdly misleading to say that you don't believe that there are fewer than 14. But if we do want to include the latter as a belief, there are probably going to have to be, on this view, quite a few stored representations regarding the number of planets (at least the 15 representations indicating that the number is >0, >1, >2, ... <14). Second, the line between what people believe and what they don't believe turns out, now, to be surprisingly occult. Does my wife believe that the solar system contains more than just the four inner planets? Well, I know she would say it does. But whether she believes it is now beyond me. Does she have that representation stored or not? Who knows?

Jerry Fodor and Dan Dennett, discussing this problem, suggest that the representationist might distinguish between "core" beliefs that require explicitly stored representations and "implicit" beliefs which are beliefs that can be swiftly derived from the core beliefs. So, if I have exactly one stored representation for the number of planets (that there are 8), I have a core belief that there are 8 and I implicitly believe that there are fewer than 14 and fewer than 134,674.6, etc. Although this move lets me safely talk about my wife -- I know she believes either explicitly or implicitly that there are fewer than 14 planets -- the occult is not entirely vanquished. For now there is a major, sharp architectural distinction in the mind -- the distinction between "core" beliefs and the others (and what could be a bigger architectural difference, really, for the philosophical representationalist?) -- with no evident empirical grounding for that distinction and no clear means of empirical test. I suspect that what we have here is nothing but ad hoc maneuver to save a theory in trouble by insulating it from empirical evidence. Is there some positive reason to believe that, in fact, all the things we would want to say we believe are either the explicit contents of stored representations or swiftly derivable from those contents? It seems we're being asked merely to accept that it must be so. (If the view generated some risky predictions that we could test, that would be a different matter.)

An alternative form of representationalism -- the "maps" view -- has some advantages. A mental map or picture of the solar system would, it seems, equally well represent, in one compact format, the fact that the solar system has more than 1 planet, more than 2, more than 3,... exactly 8, fewer than 9, ... fewer than 14.... That's nice; no need to duplicate representations! Similarly, the same representation can have the content that Oregon is south of Washington and that Washington is north of Oregon. On the language view, it seems, either both representational contents would have to be explicitly stored, which seems a weird duplication; or one would have to be core and the other merely implicit, which seems weirdly asymmetrical for those of us who don't really think much more about one of those states than about the other; or there'd have to some some different core linguistic representation, an unfamiliar concept, from which xNORTHy and ySOUTHx were equally derivable as implicit beliefs, which seems awkward and fanciful, at least absent supporting empirical evidence.

However, these very advantages for the maps view become problems when we consider other cases. For it seems like a map of the solar system represents that there are -i^2*e^0*sqrt(64) planets, and that there are 1000(base 2) planets, just as readily as it represents that there are 8. Maps aren't intrinsically decimal, are they? And it seems wrong to say that I believe those things, especially if I am disposed to miscalculate and thus mistakenly deny their truth. For related reasons, it seems difficult if not impossible to represent logically inconsistent beliefs on a map; and surely we do sometimes have logically inconsistent beliefs (e.g., that there are four gas giants, five smaller planets, and 8 planets total).

It seems problematic to think of belief either in terms of discretely stored language-like style representations (perhaps plus swift derivability allowing implicit beliefs), or in terms of map-like representations. Is there some other representational format that would work better?

Maybe the problem is in thinking of belief as a matter of representational storage and retrival in the first place.

Thursday, October 11, 2012

Berkeleyan Polytheism

I've been traveling in Spain and France, and it has been hard to find the time to pull together a full-length post. But this thought struck me a few nights ago, when I probably should have been paying closer attention to the dinner conversation: What would happen to Berkeleyan metaphysics if we swapped his monotheism for polytheism?

George Berkeley, you will recall, is an 18th-century philosopher who held that matter doesn't exist, only immaterial souls and their experiences. Your computer screen? Just an idea in your immaterial soul. Your fingers on the keyboard? Just ideas in your immaterial soul. The human brain, as seen by a neurosurgeon? Again, just an idea in the surgeon's immaterial soul. Behind these ideas are not physical substances but rather the will of God, who ensures that your sensory experiences are all nicely coordinated with each other and with the sensory experiences of other people. God ensures -- since He loves order so very much! -- that when I have an experience of seeing a red dot here and then I experience willing my eyes to move to the left I then have a sensory experience of the dot as shifting rightward in my visual field. He ensures that you and I, who experience each other as being in the same room, also have similar sensory experiences of that room, allowing for variation in perspective. Etc. It's like a very well-coordinated mutual dream. The Matrix is tame compared to Berkeley.

Berkeley, being a good Christian, believed in a single, perfect God, but what if we tweaked Berkeley's view, allowing for a limited God? What if sometimes God fell into inconsistencies, so that when you and I experience ourselves as being in the same room, sometimes I see one thing written on the board (the letter P) and you see something else (the letter Q)? God could try to cover up this error, so that when I say "I see a 'P' on the board" you hear my words as "I see a 'Q' on the board". But such cover-ups could multiply vastly: I write 'P' in my notebook, you write 'Q', then we both share our notebooks with some third party.... In the extreme, we might have to splinter off into entirely separate worlds.

Or maybe God could do a late correction: What I was seeing as 'P', I now see as 'Q', consistently with you -- and then presumably (unless God also alters my memory) I attribute my error to initial misperception. If God showed predictable patterns in such errors, maybe we could study such errors under the heading of "perceptual illusions" and see nothing so strange in them.

We might alternatively imagine more than one god, with competing goals. Without an objective physical reality to constrain them, the gods might create experiences in their followers that would be "physically inconsistent" with the experiences in other gods' followers. Perhaps God A allows his followers to experience refreshing rain after the rain dance, while God B's followers experience the scene of watching the physical bodies of the exact same followers of God A dancing for rain and being rewarded with only a dry spell. Maybe the two sects go to war and when Person X dies, the followers of God A experience X's demise as glorious bravery, while the followers of God B see X dying the death of a fleeing coward. (Person X himself presumably either willed to fight or to flee, but the others in the battle don't see his will, instead only having the visual experiences that their god chooses to deliver to them.)

Philosopher of science Thomas Kuhn says that scientists with different theories literally "live in different worlds" because their sensory experiences and their recorded data are transformed by their theoretical commitments. This is perhaps just a more radical version of that idea.

Okay, so it's not very plausible, if we're interested in the metaphysical truth of things! But maybe it's more interesting than hearing about the Barcelona-Madrid football match, if you're sitting in a restaurant full of Spaniards. Or maybe it was a side-effect of the fish.

Tuesday, October 02, 2012

Trip to Spain and France

Tomorrow I'm headed to Spain and France for a couple of weeks, and I'm not sure whether I'll have time to post. My schedule:

October 5, 1 pm start, Barcelona: "The Moral Behavior of Ethics Professors" (talk hosted by the Psychology Department).

October 6-7, Barcelona: Two day workshop on Empirical Data and Philosophical Theorizing. My talk: Oct. 6, 5-6:15: "The Psychology of Philosophy".

October 9, 11:30 start, San Sebastian/Donostia: "If Materialism Is True, the United States Is Probably Conscious" (classroom 4, Carlos Santamaria Building).

October 12, Paris, 11am-1pm: "The Crazyist Metaphysics of Mind" (Institut Jean Nicod).

As far as I'm concerned, any reader of this blog is welcome to attend. However, you might want to check with the institutions about details of access.

I will have a couple unscheduled days in Paris. I'm open to suggestions about interesting things to do.