Nozick's Machine and the Caveman

According to Julian Sanchez, Nozick's Experience Machine thought experiment is one of the big reasons he no longer think that happiness is the only rational things to pursue. As a pretty hard-core utilitarian, I had to investigate. Here is Nozick's Experience Machine in a nutshell. It's like the Matrix, man!

"Suppose there were an experience machine that would give you any experience you desired. Superduper neuropsychologists could stimulate your brain so that you would think and feel you were writing a great novel, or making a friend, or reading an interesting book. All the time you would be floating in a tank, with electrodes attached to your brain. Should you plug into this machine for life, preprogramming your life's desires?...Of course, while in the tank you won't know that you're there; you'll think it's all actually happening. Others can also plug in to have the experiences they want, so there's no need to stay unplugged to serve them. (Ignore problems such as who will service the machines if everyone plugs in.) Would you plug in? What else can matter to us, other than how our lives feel from the inside?"

We recoil instinctively from Nozick's machine. Our sensory perceptions (and eventually, our emotional states) evolved from the need to respond to the outside world and to survive in it. It seems meaningless to assert that our pleasures and pains can have any value outside of reality. It's like painted masterpiece which will never be seen, or a perfectly executed symphony that will never be heard...moot. On the face of it, Nozick's machine sounds like a powerful exhortation to stay real...to hold on to our joys and pains...to reject utilitarianism based on maximizing happiness. Yet howsoever compelling this argument seems to be, it is essentially an emotional appeal to our luddite, technophobic side rather than a sturdy philosophical argument. Let me explain with an imaginary dialog...

CAVEMAN: Urg?
PHILOSOPHY STUDENT FROM THE 31st CENTURY: Please, sir. Carry on skinning your rabbit.
CAVEMAN: Okay. What do you want?
STUDENT: Just to get to know you, really. So, life is pretty hard in the ol' hunter-gatherer days, eh?
CAVEMAN: Tell me about it, man. It's hot and buggy all the time, I'm always on the lookout for the sabertooth tiger, and I'm working at least three hour days.
STUDENT: Well, you'll be happy to know that your descendents have overcomed two of those three hardships.
CAVEMEN: How do they manage to stay cool?
STUDENT: They stay in big boxes where its nice and cool inside even if it's really hot outside.
CAVEMEN: But then how do they hunt animals?
STUDENT: They don't need to. They just swap it with little pieces of pressed tree-fibre they earn moving other pieces of pressed tree-fibre around for 8 hours a day. It's called an 'office.' Then they go back to their own box.
CAVEMEN: Do they have berries?
STUDENT: Sure...but most of the time they just drink this sweet water that kind of tastes berry-esque.
CAVEMEN: What's there to do inside the box all day?
STUDENT: Well, typically they watch other people doing stuff on another box.
CAVEMEN: You mean they can see what other people are doing from far away?
STUDENT: Yeah, well, mostly what other people are pretending to be doing.
CAVEMEN: Do they never gather around a fire and tell stories?
STUDENT: Perhaps once a year or so...mostly they like looking at squiggles on pieces of pressed tree-fiber better for stories.
CAVEMEN: But how do they have conversations? Swap information?
STUDENT: Well, there's another kind of box where you can exchange squiggles with another person, even from really far away! It's more convenient that way.
CAVEMEN: That sounds really empty and meaningless.
STUDENT: Well, you see that sharpened rock you're skinning the rabbit with right now?
CAVEMEN: Yeah?
STUDENT: That's where it all begins.
CAVEMEN [dropping the rock]: Ack! Well, it's a lot more work, but I guess I'm back to skinning critters with my teeth.
STUDENT: As you wish.
CAVEMEN: Thank the God we just started worshipping last Tuesday that you're here to tell me all this.
STUDENT: Yeah, about that "God" thing...nevermind. You don't want to know.