Tuesday, December 27, 2016

A few days ago, Skye Cleary interviewed me for the Blog of the APA. I love her direct and sometimes whimsical questions.


SC: What excites you about philosophy?

ES: I love philosophy’s power to undercut dogmatism and certainty, to challenge what you thought you knew about yourself and the world, to induce wonder, and to open up new vistas of possibility.

SC: What are you working on right now?

ES: About 15 things. Foremost in my mind at this instant: “Settling for Moral Mediocrity” and a series of essays on “crazy” metaphysical possibilities that we aren’t in a good epistemic position to confidently reject....

[It's a brief interview -- only six more short questions.]

Read the rest here.

Wednesday, December 21, 2016

Is Most of the Intelligence in the Universe Non-Conscious AI?

In a series of fascinating recent articles, philosopher Susan Schneider argues that

(1.) Most of the intelligent beings in the universe might be Artificial Intelligences rather than biological life forms.

(2.) These AIs might entirely lack conscious experiences.

Schneider's argument for (1) is simple and plausible: Once a species develops sufficient intelligence to create Artificial General Intelligence (as human beings appear to be on the cusp of doing), biological life forms are likely to be outcompeted, due to AGI's probable advantages in processing speed, durability, repairability, and environmental tolerance (including deep space). I'm inclined to agree. For a catastrophic perspective on this issue see Nick Bostrom. For a polyannish perspective, see Ray Kurzweil.

The argument for (2) is trickier, partly because we don't yet have a consensus theory of consciousness. Here's how Schneider expresses the central argument in her recent Nautilus article:

Further, it may be more efficient for a self-improving superintelligence to eliminate consciousness. Think about how consciousness works in the human case. Only a small percentage of human mental processing is accessible to the conscious mind. Consciousness is correlated with novel learning tasks that require attention and focus. A superintelligence would possess expert-level knowledge in every domain, with rapid-fire computations ranging over vast databases that could include the entire Internet and ultimately encompass an entire galaxy. What would be novel to it? What would require slow, deliberative focus? Wouldn’t it have mastered everything already? Like an experienced driver on a familiar road, it could rely on nonconscious processing.

On this issue, I'm more optimistic than Schneider. Two reasons:

First, Schneider probably underestimates the capacity of the universe to create problems that require novel solutions. Mathematical problems, for example, can be arbitrarily difficult (including problems that are neither finitely solvable nor provably unsolvable). Of course AGI might not care about such problems, so that alone is a thin thread on which to hang hope for consciousness. More importantly, if we assume Darwinian mechanisms, including the existence of other AGIs that present competitive and cooperative opportunities, then there ought to be advantages for AGIs that can outthink the other AGIs around them. And here, as in the mathematical case, I see no reason to expect an upper bound of difficulty. If your Darwinian opponent is a superintelligent AGI, you'd probably love to be an AGI with superintelligence + 1. (Of course, there are other paths to evolutionary success than intelligent creativity. But it's plausible that once superintelligent AGI emerges, there will be evolutionary niches that reward high levels of creative intelligence.)

Second, unity of organization in a complex system plausibly requires some high-level self-representation or broad systemic information sharing. Schneider is right that many current scientific approaches to consciousness correlate consciousness with novel learning and slow, deliberative focus. But most current scientific approaches to consciousness also associate consciousness with some sort of broad information sharing -- a "global workspace" or "fame in the brain" or "availability to working memory" or "higher-order" self-representation. On such views, we would expect a state of an intelligent system to be conscious if its content is available to the entity's other subsystems and/or reportable in some sort of "introspective" summary. For example, if a large AI knew, about its own processing of lightwave input, that it was representing huge amounts of light in the visible spectrum from direction alpha, and if the AI could report that fact to other AIs, and if the AI could accordingly modulate the processing of some of its non-visual subsystems (its long-term goal processing, its processing of sound wave information, its processing of linguistic input), then on theories of this general sort, its representation "lots of visible light from that direction!" would be conscious. And we ought probably to expect that large general AI systems would have the capacity to monitor their own states and distribute selected information widely. Otherwise, it's unlikely that such a system could act coherently over the long term. Its left hand wouldn't know what its right hand is doing.

I share with Schneider a high degree of uncertainty about what the best theory of consciousness is. Perhaps it will turn out that consciousness depends crucially on some biological facts about us that aren't likely to be replicated in systems made of very different materials (see John Searle and Ned Block for concerns). But to the extent there's any general consensus or best guess about the science of consciousness, I believe it suggests hope rather than pessimism about the consciousness of large superintelligent AI systems.


Possible Psychology of a Matrioshka Brain (Oct 9, 2014)

If Materialism Is True, the United States Is Probably Conscious (Philosophical Studies 2015).

Susan Schneider on How to Prevent a Zombie Dictatorship (Jun 27, 2016)

[image source]

Friday, December 16, 2016

Extraterrestrial Microbes and Being Alone in the Universe

A couple of weeks ago I posted some thoughts that I intended to give after a cosmology talk here at UCR. As it happens, I gave an entirely different set of comments! So I figured I might as well also share the comments I actually gave.

Although the cosmology talk made no or almost no mention of extraterrestrial life, it had been advertised as the first in a series of talks on the question "Are We Alone?" The moderator then talked about astrobiologists being excited about the possibility of discovering extraterrestrial microbial life. So I figured I'd expand a bit on the idea of being "alone", or not, in the universe.

Okay, suppose that we find microbial life on another planet. Tiny micro-organisms. How excited should be we?

The title of this series of talks -- written in big letters on the posters -- is "Are We Alone?" What does it mean to be alone?

Think of Robinson Crusoe. He was stranded on an island, all by himself (or so he thought). He is kind of our paradigm example of someone who is totally alone. But of course he was surrounded by life on that island -- trees, fish, snails, microbes on his face. This suggests that on one way of thinking about being "alone", a person can be entirely alone despite being surrounded by life. Discovering microbes on another planet would not make us any less alone.

To be not alone, I’m thinking, means having some sort of companion. Someone who will recognize you socially. Intelligent life. Or at least a dog.

We might be excited to discover microbes because hey, it's life! But what’s so exciting about life per se?

Life -- something that maintains homeostasis, has some sort of stable organization, draws energy from its environment to maintain that homeostatic organization, reproduces itself, is complex. Okay, that's neat. But the Great Red Spot on Jupiter, which is a giant weather pattern, has maintained its organization for a long time in a complex environment. Flames jumping across treetops in some sense reproduce themselves. Galaxies are complex. Homeostasis, reproduction, complexity -- these are cool. Tie them together in a little package of microbial life; that’s maybe even cooler. But in a way we do kind of already know that all the elements are out there.

Now suppose that instead of finding life we found a robot -- an intelligent, social robot, like C3P0 from Star Wars or Data from Star Trek. Not alive, by standard biological definitions, if it doesn’t belong to a reproducing species.

Finding life would be cool.

But finding C3P0 would be a better cure for loneliness.

(Apologies to my student Will Swanson, who has recently written a terrific paper on why we should think of robots as "alive" despite not meeting standard biological criteria for life.)

Related post: "Why Do We Care About Discovering Life, Exactly?" (Jun 18, 2015)

Recorded video of the Dec 8 session.

Thanks to Nalo Hopkinson for the dog example.

[image source]

Monday, December 12, 2016

Is Consciousness an Illusion?

In the current issue of the Journal of Consciousness Studies, Keith Frankish argues that consciousness is an illusion -- or at least that "phenomenal consciousness" is an illusion. It doesn't exist.

Now I think there are basically two different things that one could mean in saying "consciousness doesn't exist".

(A.) One is something that seems to be patently absurd and decisively refuted by every moment of lived experience: that there is no such thing as lived experience. If it sounds preposterous to deny that anyone ever has conscious experience, then you're probably understanding the claim correctly. It is a radically strange claim. Of course philosophers do sometimes defend radically strange, preposterous-sounding positions. Among them, this would be a doozy.

(B.) Alternatively, you might think that when a philosopher says that consciousness exists (or "phenomenal consciousness" or "lived, subjective experience" or whatever) she's usually not just saying the almost undeniably obvious thing. You might think that she's probably also regarding certain disputable properties as definitionally essential to consciousness. You might hear her as saying not only that there is lived experience in the almost undeniable sense but also that the target phenomenon is irreducible to the merely physical, or is infallibly knowable through introspection, or is constantly accompanied by a self-representational element, or something like that. Someone who hears the claim that "consciousness exists" in this stronger, more commissive sense might then deny that consciousness does exist, if they think that nothing exists that has those disputable properties. This might be an unintuitive claim, if it's intuitively plausible that consciousness does have those properties. But it's not a jaw dropper.

Admittedly, there has been some unclarity in how philosophers define "consciousness". It's not entirely clear on the face of it what Frankish means to deny the existence of in the article linked above. Is he going for the totally absurd sounding claim, or only the more moderate claim? (Or maybe something somehow in between or slightly to the side of either of these?)

In my view, the best and most helpful definitions of "consciousness" are the less commissive ones. The usual approach is to point to some examples of conscious experiences, while also mentioning some synonyms or evocative phrases. Examples include sensory experiences, dreams, vivid surges of emotion, and sentences spoken silently to oneself. Near synonyms or evocative phrases include "subjective quality", "stream of experience", "that in virtue of which it's like something to be a person". While you might quibble about any particular example or phrase, it is in this sense of "consciousness" that it seems to be undeniable or absurd to deny that consciousness exists. It is in this sense that the existence of consciousness is, as David Chalmers says, a "datum" that philosophers and psychologists need to accept.

Still, we might be dissatisfied with evocative phrases and pointing to examples. For one thing, such a definition doesn't seem very rigorous, compared to an analytic definition. For another thing, you can't do very much a priori with such a thin definition, if you want to build an argument from the existence of consciousness to some bold philosophical conclusion (like the incompleteness of physical science or the existence of an immaterial soul). So philosophers are understandably tempted to add more to the definition -- whatever further claims about consciousness seem plausible to them. But then, of course, they risk adding too much and losing the undeniability of the claim that consciousness exists.

When I read Frankish's article in preprint, I wasn't sure how radical a claim he meant to defend, in denying the existence of phenomenal consciousness. Was he going for the seemingly absurd claim? Or only for the possibly-unintuitive-but-much-less-radical claim?

So I wrote a commentary in which I tried to define "phenomenal consciousness" as innocently as possible, simply by appealing to what I hoped would be uncontroversial examples of it, while explicitly disavowing any definitional commitment to immateriality, introspective infallibility, irreducibility, etc. (final MS version). Did Frankish mean to deny the existence of phenomenal consciousness in that sense?

In one important respect, I should say, definition by example is necessarily substantive or commissive: Definition by example cannot succeed if the examples are a mere hodgepodge without any important commonalities. Even if there isn't a single unifying essence among the examples, there must at least be some sort of "family resemblance" that ordinary people can latch on to, more or less.

For instance, the following would fail as an attempted definition: By "blickets" I mean things like: this cup on my desk, my right shoe, the Eiffel tower, Mickey Mouse, and other things like those; but not this stapler on my desk, my left shoe, the Taj Mahal, Donald Duck, or other things like those. What property could the first group possibly possess, that the second group lacks, which ordinary people could latch onto by means of contemplating these examples? None, presumably (even if a clever philosopher or AI could find some such property). Defining "consciousness" by example requires there to be some shared property or family resemblance among the examples, which is not present in things we normally regard as "nonconscious" (early visual processing, memories stored but not presently considered, and growth hormone release). The putative examples cannot be a mere hodge-podge.

Definition by example can be silent about what descriptive features all these conscious experiences share, just as a definition by example of "furniture" or "games" might be silent about what ties those concepts together. Maybe all conscious experiences are in principle introspectively reportable, or nonphysical, or instantiated by 40 hertz neuronal oscillations. Grant first that consciousness exists. Argue about these other things later.

In his reply to my commentary, Frankish accepts the existence of "phenomenal consciousness" as I have defined it -- which is really (I think) more or less how it is already defined and ought to be defined in the recent Anglophone "phenomenal realist" tradition. (The "phenomenal" in "phenomenal consciousness", I think, serves as a usually unnecessary disambiguator, to prevent interpreting "consciousness" as some other less obvious but related thing like explicit self-consciousness or functional accessibility to cognition.) If so, then Frankish is saying something less radical than it might at first seem when he rejects the existence of "phenomenal consciousness".

So is consciousness an illusion? No, not if you define "consciousness" as you ought to.

Maybe my dispute with Frankish is mainly terminological. But it's a pretty important piece of terminology!

[image source, Pinna et al 2002, The Pinna Illusion]

Tuesday, December 06, 2016

A Philosophical Critique of the Big Bang Theory, in Four Minutes

I've been invited to be one of four humanities panelists after a public lecture on the early history of the universe. (Come by if you're in the UCR area. ETA: Or watch it live-streamed.) The speaker, Bahram Mobasher, has told me he likes to keep it tightly scientific -- no far-out speculations about the multiverse, no discussion of possible alien intelligences. Instead, we'll hear about H/He ratios, galactic formation, that sort of stuff. I have nothing to say about H/He ratios.

So here's what I'll say instead:

Alternatively, here’s a different way our universe might have begun: Someone might have designed a computer program. They might have put simulated agents in that computer program, and those simulated agents might be us. That is, we might be artificial intelligences inside an artificial environment created by some being who exists outside of our visible world. And this computer program that we are living in might have started ten years ago or ten million years ago or ten minutes ago.

This is called the Simulation Hypothesis. Maybe you’ve heard that Elon Musk, the famous tycoon of Paypal, Tesla, and SpaceX, believes that the Simulation Hypothesis is probably true.

Most of you probably think that Musk is wrong. Probably you think it vastly more likely that Professor Mobasher’s story is correct than that the Simulation Hypothesis is correct. Or maybe you think it’s somewhat more likely that Mobasher is correct.

My question is: What grounds this sense of relative likelihood? It’s doubtful that we can get definite scientific proof that we are not in a simulation. But does that mean that there are no rational constraints on what it’s more or less reasonable to guess about such matters? Are we left only with hard science on the one hand and rationally groundless faith on the other?

No, I think we can at least try to be rational about such things and let ourselves be moved to some extent by indirect or partial scientific evidence or plausibility considerations.

For example, we can study artificial intelligence. How easy or difficult is it to create artificial consciousness in simulated environments, at least in our universe? If it’s easy, that might tend to nudge up the reasonableness of the Simulation Hypothesis. If it’s hard, that might nudge it down.

Or we can look for direct evidence that we are in a designed computer program. For example, we can look for software glitches or programming notes from the designer. So far, this hasn’t panned out.

Here’s my bigger point. We all start with framework assumptions. Science starts with framework assumptions. Those assumptions might be reasonable, but they can also be questioned. And one place where cosmology intersects with philosophy and the other humanities and sciences is in trying to assess those framework assumptions, rather than simply leaving them unexamined or taking them on faith.

[image source]


"1% Skepticism" (Nous, forthcoming)

"Reinstalling Eden" (with R. Scott Bakker; Nature, 2013)