Disutility bleg

We're all familiar with Nozick's utility monster - the counterexample that eats utilitarianism. 

If someone exists who will always get more utils out of the next dollar than anyone else, then utilitarianism winds up saying you have to keep feeding the monster. And you wind up in spots that obviously conflict with common sense intuitions. Sure, it doesn't seem possible that the utility monster can exist: surely maximum utility is bounded such that it's impossible. But the thought experiment seems damning against straight utilitarianism.

But what about a disutility monster: one for whom the next dollar always provides less utility than it would for any other person. Obviously, utilitarianism says not to waste money on the disutility monster. But would this kind of disutility monster by a problem for Rawlsean setups that demand that outcomes must be set to maximise the position of the worst-off? If you maximise the position of the worst off, and the disutility monster begins from a very low-utility position and is always terrible at turning transfers into utils, you have to wind up with everyone being alike in misery right? 

And aren't disutility monsters more plausible than utility monsters? It's easy to imagine miserable people who really can't be made much less miserable; it's hard to imagine unbounded positive utility. 

Cowen's first rule is that there's a literature on everything, but I've not found this version of a disutility monster written up - at least on a quick search. 

Hence the bleg. 

Behind the veil

Michael Huemer points out the numerous problems in John Rawls' maximin criteria.

Rawls argued that, behind a veil of ignorance where you can't tell your final position in society, people would agree on a rule that maximised the position of the worst off.

Economists have generally argued this is nonsense - it implies a degree of risk aversion behind the veil that is never seen anywhere else. 

Huemer goes through the problems. A snippet [note that OP means the Original Position, behind the veil]:

II. Diminishing Marginal Utility

Wealth has sharply diminishing marginal utility, above a certain minimum level. So there’s not much reason for the parties in the OP to try for greater wealth, above the amount they would get under the Difference Principle.

Replies:
a) That’s an argument for not maximizing expected wealth. It’s not an argument for not maximizing expected utility. The diminishing marginal utility of wealth is already taken into account by utilitarianism (obviously), so it can’t be an argument against utilitarianism.
b) If there is really a minimum amount of wealth that you need for a decent life, and additions above that amount give little or no improvement in your welfare, that still wouldn’t support the difference principle. Rather, it would support the principle, “maximize the number of people who are above the minimum.”
c) Rawls hasn’t supported those factual assumptions anyway. It’s plausible that there is a minimum amount of wealth needed to have a decent life, and there is also an amount above which you get no noticeable benefit from more wealth. But those two amounts are obviously not the same amount.

 

Effective Altruism

I'll be chairing a discussion with Peter Singer in Christchurch in September. If you're anywhere in the neighbourhood, by which I mean within a 3-hour flight, you should attend.

I have never loved and hated and been changed by a book as much as Singer's Practical Ethics. I threw it across the room more often than any other. Actually, I think it's the only book I've ever hurled against the wall. But his arguments are almost impossible to resist.

The morning that I got the call from the Christchurch Festival inviting me to this, I'd walked in to work with Eleanor, then aged 4. On the way, that morning, I'd explained trolley problems to her - as you do with your four year old. She proved a very strict utilitarian. She then went on to propose ever differing bundles of who might be on which rail lines and whether you'd pull the switch - she was basically running hypothetical choice experiments to find out my marginal willingness to pay across options. Most of the options involved kitties of varying cuteness against family members, so it was all pretty easy for me. Then I got the call asking to come in to talk with Peter Singer. It was a great day.

I'll be discussing Singer's latest work on effective altruism. I'm really looking forward to it. Hit the link at the top to register and get tickets.

ON EFFECTIVE ALTRUISM


How can we do the most good? Peter Singer, often described as the world’s most influential living philosopher, presents a challenging new movement in the search for an ethical life. Effective altruism requires a rigorously unsentimental view of charitable giving, urging that a substantial proportion of our money or time should be donated to the organisations that will do the most good with those resources, rather than to those that tug the heartstrings. Chaired by Eric Crampton.
Peter Singer is the author of more than 20 books, including the groundbreaking work on ethics, Animal Liberation, The Ethics of What We Eat, The Life You Can Save, and his latest, The Most Good You Can Do. He teaches philosophy at Princeton and Melbourne Universities.
Eric Crampton is Head of Research with The New Zealand Initiative in Wellington and Adjunct Senior Fellow with the Department of Economics and Finance at the University of Canterbury. He blogs at Offsetting Behaviour.

Another fun bit: the Christchurch festival folks invited me, in part, because I'd blogged on the ridiculousness of charity races some time ago.

Samuelson versus Schumpeter, and a few philosophical questions

SMBC reckons Samuelson got around.



They've forgotten about Joseph Schumpter:

Early in life I had three ambitions. I wanted to be the greatest economist in the world, the greatest horseman in Austria, and the best lover in Vienna. Well, I never became the greatest horseman in Austria.

John Maynard Keynes was also rather prolific.

Friedrich Hayek moved to Arkansas so he could divorce his wife and marry his second cousin.*

Economists are interesting people.

* Jokes about ACT being fans of Hayek would be cheap shots. Whyte answered the question as any philosophy lecturer should.

I, for one, wish we could have an all-candidates debate in which each party leader is required to give a straight answer to each of the following:

• You are standing at a railway switch. A runaway train is hurtling down the hill and will run over five people with certainty. If you throw the switch, it will divert to another track and will run over only one person. Do you throw the switch? Does your answer depend on whether the five people are wearing your party's or your opponent's t-shirt?
• If you agreed that we should throw the switch, would you also support compulsory vaccination? Why not? You know that you're doing exactly the same thing here as standing by the switch, watching the train hurtle towards the five people, right? Except that, given the safety of vaccinations, it's more like a thousand people killed for every adverse reaction to vaccination.
• If your answer, above, was that compulsory vaccination interferes with legitimate individual autonomy for too little public health gain, explain your stance on the regulation of alcohol, tobacco, marijuana and heroin. Does compulsory vaccination do more to violate individual autonomy than banning the private consumption of tobacco or marijuana, or than taxing the heck out of alcohol?
• A young person lives in Temuka and moves to Auckland in search of a better life. The young migrant finds a far better job than would have been available in Temuka and is much happier than otherwise. He outbids a native Aucklander for a house, but only slightly. A person who lives in Auckland also, as consequence, gets a slightly worse job than she otherwise would have gotten. Should the government ban migration from the South Island to Auckland? 
• Would your answer be different if the young person lived in East Timor instead? What moral theory allows you to distinguish between these two cases?
• A man cheats on his wife without her knowledge; she is never aware that it has happened. Has he done her harm? If so, should adultery be banned? Why not?
• A married couple fall in love with a third person. They live together as a family. They raise their children together. They wish their relationship to enjoy formal recognition to ensure easier survivorship rights in case of death and so that their children will be more comfortable in talking about their {Three Moms, Moms and Dad, Dads and Mom, Three Dads}. What harm would be done were they allowed formal legal recognition of their relationship? Why should polygamy be banned? What set of consistent moral principles leads to {allow adultery, ban polygamy}?

Feel free to propose other questions for the never-will-happen all-candidates' debate.

Dirty hands

I appreciated this bit in Art of Theory's interview with Michael Walzer (HT: Xavier Marquez):

Walzer: The argument of my piece on dirty hands, which is also the argument summed up in that phrase, is that sometimes it’s necessary in politics to do things that it’s wrong to do, which translates into the right thing to do being the wrong thing to do. That’s the incoherence.

What philosophers mostly believe is that the right thing to do is what, all things considered, is the right thing to do. The notion of getting your hands dirty implies that you’re doing something which is wrong and that’s what I was trying to get at in the article. You want political leaders who know that x is the wrong thing to do, because you want them to do it only in extremis. You want them to do it only at the last minute, when nothing else will work, and when there’s some looming disaster. It’s a kind of utilitarianism of the last moment.

You begin by rejecting the maxim “do justice even if the heavens fall,” and instead choose the maxim “do justice until the heavens are about to fall, and then do whatever you have to do to stop the heavens from falling.” You have to know that your actions at that last moment are something brutal, cruel, wrong. Otherwise you will do it too soon, and too often.

That's not far from what I think about voting: only do it if there's a lot at stake and if it's looking really close. And about a few other things too.

There should always be some utilitarian/consequentialist side constraint.

Thought experiments and taking offence

I love Brad DeLong's academic work. He's way smarter than me and, more importantly, clearly works much much harder than I do. And he tackles interesting questions. But every time I check his blog, I get an awful "Everyone in the world is evil or stupid or both except Brad and a few of his friends" vibe.

I'd not been there for a while, but switching to The Old Reader (for now) from Google Reader messed up my RSS habits. And so, there I was, looking at Brad DeLong saying that Steven Landsburg is the stupidest man alive and that "the University of Rochester has a big problem" - presumably Landsburg's continued employment there.

What was the cause? A piece at Gawker taking great offence at a thought experiment Landsburg proposed. I'll link Gawker at the end so you're not tempted to read it before reading the original Landsburg piece.

In grad school, we had a lot of fun with thought experiments of this sort. The classic one is Nozick's experience machine. Step into the machine and you'll experience a simulated life much better than the one you'd otherwise live; moreover, you'll never remember that you're actually in the machine. If you stay out of the machine, there has to be something that matters more to you than experienced utility. 

Tyler Cowen liked to ask a variant on it in our Economics & Philosophy class: World B is identical to World A, as far as you are ever able to observe, but in World B, your wife has been cheating on you for years and you never ever knew it, nor will you ever know it. The worlds are identical except for the unknown-to-you fact of your wife's infidelity. Are you worse off in World B? If so, clearly state exactly how, and make that consistent with other things you believe about utility. 

So, what was Landsburg's offensive thought experiment? Recall that the rules of thought experiment club are that you don't add in auxiliary assumptions but stick to what's stated in the thought experiment. Landsburg asked a series of three questions, then wanted to know why our answers to 1 and 2 might differ from our answer to 3. Here they are.

Farnsworth McCrankypants just hates the idea that someone, somewhere might be looking at pornography. It’s not that he thinks porn causes bad behavior; it’s just the idea of other people’s viewing habits that causes him deep psychic distress. Ought Farnsworth’s preferences be weighed in the balance when we make public policy? In other words, is the psychic harm to Farnsworth an argument for discouraging pornography through, say, taxation or regulation?

That's scenario 1. Most economists just ignore that psychic harm - the world's essentially impossible to evaluate when we add this kind of thing in. Further, Farnsworth could pay other people not to watch pornography if he really cared about it that much. But we could assume that away to stick within the proper confines of the thought experiment: say transactions costs prevent it. Is pyschic harm of this sort admissible in the utilitarian calculus? Here's scenario 2:

Granola McMustardseed just hates the idea that someone, somewhere might be altering the natural state of a wilderness area. It’s not that Granola ever plans to visit that area or to derive any other direct benefits from it; it’s just the idea of wilderness desecration that causes her deep psychic distress. Ought Granola’s preferences be weighed in the balance when we make public policy? In other words, is the psychic harm to Granola an argument for discouraging, say, oil drilling in Alaska, either through taxes or regulation?

Actually, policy does weigh Granola's concerns. It's counted as existence value over and above option value or use value. Sound analyses don't put much weight on it, but it does sometimes count. If I get existence value from thinking heroic Randian thoughts about oil derricks and man's mastery of nature, that gets ignored in the cost-benefit analysis for some reason. But, again, all these kinds of pyschic distress are treated pretty dismissively in economics. And now the third and controversial question:

Let’s suppose that you, or I, or someone we love, or someone we care about from afar, is raped while unconscious in a way that causes no direct physical harm — no injury, no pregnancy, no disease transmission. (Note: The Steubenville rape victim, according to all the accounts I’ve read, was not even aware that she’d been sexually assaulted until she learned about it from the Internet some days later.) Despite the lack of physical damage, we are shocked, appalled and horrified at the thought of being treated in this way, and suffer deep trauma as a result. Ought the law discourage such acts of rape? Should they be illegal?

If we take this as a parallel thought experiment, the only trauma here allowable is the psychic distress, which we otherwise typically ignore.

It is a hard question and so a good one. All our intuitions tell us to condemn the third scenario while dismissing the psychic harms in the first two. But if we stick within the confines of the thought experiment, it's hard to distinguish the cases. We can say the psychic harm is worse in the third case, and it would be in the real world, but it's not hard to have a thought experiment Granola McMustardseed who gets more psychic harm from oil drilling than from being in Scenario 3. Or a Scenario 3 victim who never learns that it happened - a case pretty close to Cowen's World A vs World B.

I don't have any great answer other than that when we step away from the thought experiment and into the real world, a rule allowing Scenario 3 that imposes psychic harm no greater than that imposed in Scenarios 1 & 2 would also necessarily allow much much greater harm because we cannot set rules only allowing Scenario 3. But that's a cop-out, because even if we could do it in the real world, I'd still want it banned - in the same way that I think I'm worse off in Cowen's World B and that I wouldn't want to step into Nozick's machine. My maximand isn't just experienced utility.

Meanwhile, Gawker turns it into a story about how Landsburg thinks rape is OK and DeLong signs onto their interpretation. The contrast between the quality of comments at Landsburg's post and DeLong's is interesting too... Landsburg's commenters wrestle with a difficult thought experiment; DeLong's want Landsburg fired.

Rents and the social nexus

I postponed grad econometrics by a year to take James Buchanan's Constitutional Political Economy course. Buchanan there argued* that taxation is legitimate because any income above that which would accrue in the state of nature can be seen as a rent stemming from participation in the social nexus that would have been impossible absent the state. So taxation and redistribution wasn't theft.

Leaving aside problems of how to accrue the gains where the sum of marginal products is greater than one, I asked Professor Buchanan instead whether we could similarly argue for forced live kidney donations by folks over the age of 35 or so. Life expectancy beyond that which would have accrued in the state of nature could similarly be viewed as a rent. Buchanan favoured somewhat egalitarian income redistributions but not somewhat egalitarian kidney redistributions; I don't recall any particular reason why the one was acceptable but the other wasn't.

I'm reminded of this because Blunt Object points to Megan McArdle's similar drawing of parallels:

John Quiggin complains that what the classic essay I, Pencil actually shows is the wonders of a mixed economy, not the market. The essay traces all the amazing transactions that need to occur for a simple pencil to be made, pointing out that not one of the people involved could make a pencil by themselves, and most of them don't even know that they're involved in producing a pencil. But what about the US Forestry Service? Rail rights of way? The education system?

This is an argument to which the left-wing has a great deal of recourse whenever anyone suggests that people have a right to keep what they earn from voluntary transactions. You can only make money in the context of society, and so society has a right to regulate your transactions, and seize the proceeds, in any way that society sees fit.

And yet, the argument applies just as well to our sex lives or our political beliefs: they take place in the context of all sorts of government protections, from rape prosecutions to whistleblower laws. Without markets and the government, the "anything between two consenting adults" morality to which the majority of the elite subscribes would be impossible; the closest substitute for these things is family, and families have a very clear, deep, and persistent interest in regulating the sexual behavior of their members.

I'd expect that Kings could also thereby have justified Droit du Seigneur.

The argument goes farther than Megan thinks. If we only had a life expectancy of about 35 years back in the state of nature, then every year of life beyond that is a rent subject to appropriation or redistribution. So is every year of life for someone who would have died in infancy in the state of nature.

Quod nimis probat, nihil probat.

* Alas, all my notes are in my still-red-stickered office, so I can't double check.

Cryonics

Kerry Howley's piece in the New York Times Magazine is lovely.

Robin Hanson wants to be cryogenically preserved on death; his wife, Peggy, works in a hospice helping folks deal with death and is no fan of cryogenics.

Among cryonicists, Peggy’s reaction might be referred to as an instance of the “hostile-wife phenomenon,” as discussed in a 2008 paper by Aschwin de Wolf, Chana de Wolf and Mike Federowicz.“From its inception in 1964,” they write, “cryonics has been known to frequently produce intense hostility from spouses who are not cryonicists.” The opposition of romantic partners, Aschwin told me last year, is something that “everyone” involved in cryonics knows about but that he and Chana, his wife, find difficult to understand. To someone who believes that low-temperature preservation offers a legitimate chance at extending life, obstructionism can seem as willfully cruel as withholding medical treatment. Even if you don’t want to join your husband in storage, ask believers, what is to be lost by respecting a man’s wishes with regard to the treatment of his own remains? Would-be cryonicists forced to give it all up, the de Wolfs and Federowicz write, “face certain death.”

I'm not opposed to cryonics, but I've not signed up. It's a form of Pascal's wager that offers far better odds than heaven, but still odds that seem vanishingly slim. I'd put non-trivial odds on a future mapping of a frozen brain being sufficient to generate whole brain simulation, but lower odds that the frozen brain can be revived. As Alcor puts it:

Cryonics is not a belief that the dead can be revived. Cryonics is a belief that no one is really dead until the information content of the brain is lost, and that low temperatures can prevent this loss.

And while I place positive value on there being some simulated version of me existing a couple of centuries from now, I still probably irrationally place undue weight on that it's this instance of this consciousness that wakes up rather than a copy. If cryonics were available at low cost, I'd sign up. But it isn't exactly cheap. Then again, lots of medical treatments are far more expensive. As Howley notes:

Robin’s expertise extends to the economics of health care, a domain in which enormous amounts of money are spent on experimental procedures with only a small chance of extending life. Like many cryonicists, he says he thinks of bodily preservation as experimental end-of-life medical care, and it is within a medical context that he typically introduces the subject of cryonics to his health economics class at George Mason. His students rarely accept this framing. “We spend most of the semester talking about how people are obsessed with taking any small chance at living longer,” Robin says. “And then when we get to cryonics, it’s: Well, who needs to live longer? What’s the point of living anyway? Why can’t we solve global hunger?”

In other words, while his wife says that medical technology has an unfortunate stranglehold on the way we die, Robin longs to claim the mantle of medical science for his attempt to avoid death altogether. But here he doesn’t expect to succeed, and as with most societal attitudes that contradict his intuitions, he’s got a theory as to why. “Cryonics,” Robin says, “has the problem of looking like you’re buying a one-way ticket to a foreign land.” To spend a family fortune in the quest to defeat cancer is not taken, in the American context, to be an act of selfishness. But to plan to be rocketed into the future — a future your family either has no interest in seeing, or believes we’ll never see anyway — is to begin to plot a life in which your current relationships have little meaning. Those who seek immortality are plotting an act of leaving, an act, as Robin puts it, “of betrayal and abandonment.”

None of this forms a binding constraint in our house. It's rather that, given low odds of successful recovery from cryonics, paying off the mortgage gets higher priority.

If I'm ever able to get over my irrationalities about prioritizing this instance of me over potential alternatives, I suppose I'd have to upweight cryonics.

For folks excessively interested in this sort of thing, check this mindbending piece of science fiction philosophy by Daniel Dennett.

And Robin comments on the article here.

Court philosophers

At a philosophy seminar last week, the speaker argued claims that "taxation is theft" are nonsensical because property rights are defined legislatively as a social construct: consequently, taxation can never be theft because the property was never yours to begin with. You only held rights subject to the constraint that some of the property would be taken by the state.

I'm not much of a natural rights guy, mostly because I figure my natural right in the state of nature would be to run away as fast as I could from folks with clubs or, preferably, to have allied with some guy who's really good with a club to protect me from others - maybe I'd do his homework for him or something.

But I'd still reckon that the guy with the club in the state of nature would be violating my rights. I own myself, regardless of statutory convention. Suppose that statutory convention held that anyone who wears blue on a Thursday that's a full moon becomes slave of the state. Even were I to screw up and thereby legally become a slave, I'd argue that my right to self ownership has been infringed upon rather than that my right to self ownership existed only subject to statutory convention.

And I worry about conceptions of right that say that, because something's defined as a statutory convention, rights-talk goes out the window.

I can imagine the philosophy seminar of a thousand years ago where the Court Philosopher argues against the man whose bride was ravished by the Prince on her wedding night, saying that the maidenhead always belonged to the Prince by Droit du Seigneur and that it consequently wasn't a violation. (yes, yes, Droit du Seigneur is largely apocryphal, but thought experiments are allowed in both philosophy and economics.)

Is there an argument for "taxation isn't theft" that doesn't also support "Droit du Seigneur isn't rape"? The best answer, I'd think, would have to rely on a contractarian turn where we had hypothetical agreement behind the Veil to a set of rules allowing for taxation. But the contractarian turn requires self-ownership behind the Veil or something a lot like it, otherwise hypothetical agreement isn't necessary. But if we want to deny those pre-existing rights, I'm having a hard time seeing a mechanism for getting "taxation isn't theft" without risking "Droit du Seigneur isn't rape". If it's just "whatever is agreed to by majority is just, and the majority would support only one of those", we get the usual obvious problems. A "justice is efficiency" argument would be coherent, but the speaker was making the argument for the moral necessity of a highly progressive tax system in order to fund heavy redistribution: an equity argument rather than efficiency. If it's instead "justice is maximizing my social welfare function which considers taxation to be ok because the statutory convention in this case I find fine but not droit du seigneur because that statutory convention is repugnant", well, preferred SWFs are like belly-buttons...we all have one.

I didn't press him on this line as there were a few bigger problems in the paper: namely, that if his bottom line were that certain government services must be provided, he'd perhaps do better by not having a hard commitment to the justice attributes of any particular tax system and instead try to cover equity concerns via spending programmes after having raised the necessary amount of tax by the most efficient means possible. And the norm in philosophy seminars seems to be somewhat different from the economics norm. In all disciplines, a fair bit of question time is devoted to giving questioners the opportunity to show how smart they are. In economics, this tends to be done via penetrating questions and holding the speaker to providing an answer; in philosophy, it seems more to be via wandering stories that seem not actually to have any kind of question attached to them. In econ, folks using the latter mode attract snickers; in philosophy, it's me.

"Me" got bigger

Robin Hanson and Bryan Caplan are blogging one of the most fun arguments they've had, or at least one of the ones I enjoyed most at lunch as a grad student.

Suppose you're scanned, atom by atom, and a replica of you is made. Hanson then says '"me" got bigger'. The replica shares all of your memories and purposes; it seems pretty reasonable to view it as an extension of you. I'm with Hanson up to this point.

Hanson then claims to be indifferent between whether he or his replica is shot following replication. Either way "me" gets smaller. So Robin would have no problems in stepping into a Star Trek teleporter: the teleporter destroys the current instance of 'him' but creates an identical new instance elsewhere who materializes remembering having stepped into the teleporter. I'm with McCoy: there's no way I'd step into the teleporter. Shuttlecraft only, unless the alternative is that the only instance of 'me' otherwise would be destroyed (yes, I'd teleport away from the planet that was imploding if the shuttle couldn't get there in time). And then Hanson would needle by asking why you're ever willing to go to sleep.

Robin and Bryan are currently arguing this with respect to cryonics. Robin's happy to go for cryonics even if it only gives the chance of having a simulated upload of his brain run on a computer sometime down the line; Bryan doesn't think that's good enough. I'd take the upload over nothing, but would still prefer waking up thawed. And Robin would of course demolish that line of argument: whatever is woken up a century or two from now will only be 'you' to the extent that the neurons are in the right positions with the right charges, so there's no particular reason to prefer that the physical instance of your current brain is woken up or some replica of it or a neural net scan that's running as an upload on a computer. In all cases, something would wake up with a memory of having been 'you'.

If you're a materialist, it's hard to avoid Hanson's conclusion. But I still want to give a higher priority to the current instance of 'me' than to any potential extensions. I remain a "me-utilitarian", where higher weights are placed on instances of 'me' closer to the current instance.

Zombies and Epiphenomenalism

NCIB ROFL gives a nice daily roundup of amusing articles published in the PubMed database. Highlights include medical articles on optimal methods for extracting the zipper-entrapped penis an ergonomics article on the force required to drag sheep over various surfaces.

Perhaps there's no equivalent in the humanities because it would be too easy. Here's the latest from Dialogue, a Canadian philosophy journal. Andrew Bailey's work on Zombies and Epiphenomenalism. doi:10.1017/S0012217309090076

ABSTRACT: This paper examines the relationship between the claim that zombies are logically/metaphysically possible and the position that phenomenal consciousness is epiphenomenal. It is often taken that the former entails the latter, and that therefore any implausibility in the notion of conscious epiphenomenalism calls into question the genuine possibility of zombies. Four ways in which the zombist might respond are examined, and I argue that two — those most commonly encountered — are inadequate, but the others — one of which is rarely formulated and the other new — are more forceful. The upshot, nevertheless, is that the zombist may indeed face an unwelcome commitment to conscious epiphenomenalism.

If there actually are zombies, an unwelcome commitment to conscious epiphenomenalism is the least of our worries.

I had a look because of the intriguing title, but the article goes into some interesting work on theory of mind. I was unaware that the metaphysical possibility of zombies had been raised as a counterexample against physicalist theories of mind. Bailey concludes:

Finally, however, to the degree that the notion of causal gaps (or causal agents that are neither physical nor phenomenal) can be made plausible, it might be possible for the zombist to evade even this commitment and sever the link between the zombie hypothesis and phenomenal epiphenomenalism entirely.

This last move will be attractive to — perhaps even necessary for — the zombist, given the widespread wariness that exists, among physicalists and anti-physicalists alike, about phenomenal epiphenomenalism. Yet it has as yet been little explored, and remains highly speculative. Perhaps this is the front on which the next battle of the “zombie wars” is to be fought.

I'll have to ask the philosophers at the staff club to fill me in on the zombie wars.