Friday, April 22, 2016

Desirism Book - Part 0006 - Nozick's Experience Machine

To the regular readers of my blog, I am sorry. I addressed Nozick's experience machine in a post outside this series just a few days ago. However, I have come to realize that it has a place in this series, right about here. Much of what I say here will repeat what I wrote about a week ago, altered slightly to fit into the context of this series.

We have one person (Alph) with one desire (a desire to gather stones or a desire "that I am gathering stones".)

I have just mentioned that what matters for a person with a desire that P are states where P is true. Insofar as Alph desires to gather stones, Alph has a motivating reason to realize states where the proposition, “I am gathering stones” is true.

Robert Nozick has asked that we consider the option of an experience machine – a machine that will artificially generate the impressions of any given state of affairs. If Alph were hooked up to this experience machine, it would be impossible for Alph to distinguish in virtue of sensation between actually gathering stones and having the machine-generated sensation of gathering stones.

So, would Alph choose to be hooked up to the experience machine?

We may assume, to provide extra incentive, that the real world has a limited number of stones, requiring that Alph spend some of his time scattering stones so that he can gather them again. However, the experience machine world will have an unlimited amount of stones, allowing Alph to have the permanent sensation of gathering stones.

On the model we are establishing here, Alph would respond to the offer of the experience machine by saying, "No, thank you. Your experience machine provides nothing of value. I have no reason to accept your offer."

The reason for this response comes directly from the fact that Alph’s desire to gather stones is a desire that the proposition, “I am gathering stones” be made or kept true. The experience machine cannot make it the case that the proposition, “I am gathering stones” is true. In fact, as long as Alph is hooked up to the machine, the proposition, “I am gathering stones” is false – and thus a state of affairs Alph has no interest in.

We can see this distinction better if we take a different example.

In this example, Betty has a desire that her children are healthy and happy. She is given a choice between entering the experience machine where she will get impressions that her children are in perfect health and happy – while their children are, instead, taken to a torture chamber.

Or, she can choose to enter the experience machine where she will be given impressions that her children are tortured mercilessly while, in fact, her children are healthy and happy.

Insofar as Betty truly desires that her children are healthy and happy, she has reason to choose the second option, and no reason to choose the first option. The second option is the only available option that makes the proposition “my children are healthy and happy” true.

There are some desires where their objects are such that the experience machine can make them true. Insofar as we focus on these desires, an agent will have reason to enter the experience machine.

The person who enjoys the experience of eating a steak, but wishes to avoid the cholesterol, calories and other possible health effects or wishes that no cow be killed to provide the steak, will have reason to enter the experience machine.

In fact, all of these caveats after the word “but” are optional. They can be stricken from the example. As long as the agent has a desire “that I am having the experience of eating a steak” rather than a desire “that I am eating a steak”, the agent has a reason to enter the experience machine. The reason the experience machine is successful is because it has the capacity to make the proposition, “I am having the experience of eating a steak” true – so it fulfills the desire in question.

The idea that a desire that P is a motivational attitude that the proposition P is to be made or kept true is to be understood literally. This is going to play a significant roll in what follows.

2 comments:

David Jacquemotte said...

Something struck me here that I am having trouble reconciling. While Alph may have the desire to be gathering stones, his experience of gathering stones is unchanged whether he really is gathering or inside the experience machine. All input into our brain and hence whether we think our desires are being fulfilled go through a kind of experience machine already (our brain). He may not have reason to CHOOSE to go in, but once he is in, he would have no reason to get out. As far as he is concerned, his desire is objectively being fulfilled, until someone comes along and gives him the "red pill". Except there isn't going to be anyone offering red pills. Since the state of actually gathering stones and only experiencing gathering stones is indistinguishable as far as Alph is concerned, wouldn't he be ambivalent about the offer? Why think he would care whether his desire is being objectively satisfied or not unless you are basing that on the additional hidden desire that his desires be objectively fulfilled.

Alonzo Fyfe said...

He does have a reason to leave the experience machine - he just doesn't know it.

Take a slightly different case - that of a parent wishing the well-being of their child. Just as with gathering stones, the experience of having one's child well-off within the machine is qualitatively identical to the experience of having their child well-off outside of the experience machine.

However, tell the parent, "Your real child is suffering horribly while this imaginary child is well-off" and give them offer to leave the experience machine, they will have a reason to take the offer.

This reason did not magically appear as soon as the offer was made. It always existed - though the agent did not know that it existed.

It is easy to confuse a desire for the experience of gathering stones for the desire to gather stones. The experience machine can certainly fulfill the desire for an experience of gathering stones, but cannot fulfill the desire to gather stones. Similarly, the experience machine can certainly fulfill the desire for the experience of having children who are well-off, but cannot fulfill the desire that one's children are well off.