Nozick's gedanken machine

Tue 13 Jan 2009 02:20 PM

A propos of nothing, I've been thinking about Nozick's experience machine argument. In the SEP, Roger Crisp summarizes the argument in this way:

Imagine that I have a machine that I could plug you into for the rest of your life. This machine would give you experiences of whatever kind you thought most valuable or enjoyable—writing a great novel, bringing about world peace, attending an early Rolling Stones' gig. You would not know you were on the machine, and there is no worry about its breaking down or whatever. Would you plug in? Would it be wise, from the point of your own well-being, to do so? Robert Nozick thinks it would be a big mistake to plug in: "We want to do certain things ... we want to be a certain way ... plugging into an experience machine limits us to a man-made reality."
Crisp calls this a "weighty objection to hedonism of any kind." In context, it is clear that he takes it to be an important and decisive objection to hedonism.

When I first read Nozick as an undergrad, I was impressed by this argument. Nozick does not attribute the upshot of the argument to himself. He suggests that you, the reader, would not plug into the machine and that this is sufficient to defeat hedonism. This is a kind of rhetorical trick, though, because it is not obvious that we would not enter the machine.

I didn't notice this trick initially. I was discussing the argument with a non-philosopher friend who said she would certainly enter the machine. On reflection, I began to suspect that much of my disinclination to enter was due to worries about how it would work. We are told that the machine would provide us with whatever experience we would enjoy, but we know that technology has limitations and is prone to breakdown. I can easily imagine scenarios in which I get in the machine and it goes horribly wrong: A lightning strike zaps the machine and fries my brain. The mechanism damages my nervous system and ultimately turns me into a psychotic leper. Economic conditions require it to be unplugged in a couple of years, and I stumble out unable to cope with a world that has changed in my absence. And so on.

We can stipulate as part of the thought experiment that the machine is reliable, safe, and will continue to operate without interruption once I step inside. We can even stipulate that I know these things to be the case. But stipulating these things does not scrub my intuitions of such concerns. If I still feel disinclined to enter, my disinclination does not come with a ticket saying why I am disinclined. My suspicion of technology is part of the way that I think about machines and cannot be waved away so easily. And it would be unwise of me to alter my psychology so that I could it could. It is better for me to always distrust claims that a gizmo is "totally reliable" and "a sure thing", because commercials bombard me with such claims every day.

Nozick's objection that the machine merely gives us 'man-made reality' plays on similar worries. The natural world contains richness and depth that (I worry) would be left out of any virtual world. We can stipulate that the experience machine provides all the richness of the real world, but it is not clear that I can fully accept that stipulation.

At the time, I also thought that my disinclination resulted from worries about other people. My friends and family might be unhappy if I entered the machine, and if I stayed I would be able to make people on balance happier. We might stipulate that other people will all enter their own machines, but perhaps this strains the imagination too much. It suffices to note that this source of disinclination is an argument not against hedonism but against egoism. I am concerned for more than my own happiness, but that doesn't tell us whether the machine can provide happiness or not.

Crisp gives three examples of things I could do in the machine: writing a great novel, bringing about world peace, attending an early Rolling Stones' gig.

He insists that there is a difference between the experience of writing a great novel and actually writing a great novel, but this is ambiguous. He says, "the experience of really writing a great novel is quite different from that of apparently writing a great novel, even though 'from the inside' they may be indistinguishable." Certainly there is a difference between writing a novel which one merely thinks is great and writing a genuinely great novel, but writing a novel in the virtual environment provided by the machine would still count as writing a novel. If it were a great novel, then one would have written a great novel.

The example of attending an early Rolling Stones' gig is similarly problematic. If you have the experience of attending the gig, then it would count as an instance of the relevant performance type.

Of course, bringing about world peace in the machine would not be as good as really bringing about world peace. But this does not settle the question of whether world piece is desirable because of the terrible experiences that result from war or because of something else.