I have a bit of a flu today and my mind is in somewhat of a fog.
However, I wish to try to answer Kmeson’s question about Desire Utilitarianism;
Question: Consider two agents, A and B. Each has 10 equal desires. Each currently has 5 fully satisfied desires, and 5 unsatisfied desires. You as agent C, and desire utilitarian, have the ability to fulfill 2 of agent A's desires, at a cost of 1 of agent B's desires. You may continue to trade at a two for one ratio as much as you would like. What if any is the desire utilitarian argument against minimizing agent B's expensive desires in favor of agent A's cheap ones?
First, as Martino has pointed out in answering this question in the comments, there is a difference between “desire utilitarianism” (the right act is the act that a person with good desires would perform, where good desires are those that tend to fulfill other desires), and “desire fulfillment act utilitarianism” (the right act is the act that fulfills the most desires).
To illustrate the difference between these two theories, I wish to bring forward the answer I gave to Atheist Observer’s question on the same post (with some slight modifications to fit the context here):
Desires are persistent entities - they continue to exist through a range of choices.
Assume the following set of choices with the following options:
Choice 1a vs 1b
Choice 2a vs 2b
Choice 3a vs 3b
Choice 4a vs 4b
Choice 5a vs 5b
In each case, the A option is the option that will fulfill the more and stronger desires.
There are two possible desires.
D1 will motivate an agent to do 1a, 2a, 3a 4b, and 5a.
D2 will motivate an agent to do 1b, 2b, 3b, 4a, and 5b.
When it comes to Choice 4, desire-fulfillment act utilitarianism says to do 4a. However, the only agent who can do 4a is the agent with the Desire D2. But this agent would be thwarting a whole stack of other desires, so we do not want to encourage people to acquire desire D2. We want to encourage him to have desire D1. Which means, we want to condemn the person who will do 4a (to discourage this desire) rather than praise him.
That is to say, where desire-fulfillment act utilitarianism says that 4a is the right act, desire utilitarianism itself says 4b is the right act – the act that deserves our praise, because the person who does 4b is the better person, the person with the better desires.
Another important element we are going to introduce here is that ‘ought’ implies ‘can’ – and its corollary ‘cannot’ implies ‘it is not the case that one ought’. We are concerned here only with malleable desires – desires that we can alter through social conditioning. It is not the case that a person ought to have a desire that he cannot have.
The only type of person who will always do what (he believes to be) the best act in desire-fulfillment act utilitarian terms is a person with only one desire – to fulfill other desires. This person can have no desire for sex, aversion to pain, preference for chocolate over vanilla, fear of heights, love of adventure, or any type of love for that matter. Nobody can be this type of agent, so nobody ought to be this type of agent.
So, now we go back to Kmeson’s question.
Kmeson is asking what C should do, and is putting the option in terms of an act that will fulfill more of B’s desires than A. In other words, Kmeson is raising an objection to desire-fulfillment act utilitarianism (do that act that fulfills the most desires), not desire utilitarianism itself.
Desire utilitarianism would first look at these desires that A and B have and start to ask questions about them. By assumption, A has desires that tend to thwart other desires (the only way to fulfill A’s desires is by thwarting B’s desires). So, A has bad desires. Desire utilitarianism argues that we should be raising our children in such a way that we promote desires that tend to fulfill other desires, and inhibit desires that tend to thwart other desires. We are to use our social powers of condemnation to prevent somebody like B from coming into existence.
As I said above, desire utilitarianism only applies to desires that are malleable. So, I need to add some assumptions about malleable and fixed desires, or desire utilitarianism is not even relevant. Let us assume that B’s desires are fixed (e.g., aversion to pain), where A’s desires are malleable (e.g., desire to cause pain).
We are not going to prevent the acquisition of these desire-thwarting desires by rewarding the people who have them. If C acts so as to fulfill A’s (bad; desire-thwarting) desires, he is simply encouraging the development of these bad desires in others. He’s making the situation worse.
Instead, C should be thwarting A’s bad desires as a way of discouraging others in society from adopting these desires. In fact, C should be condemning and criticizing A himself for having these desires. In this way, C has the power of weakening these bad desires in A, creating a society where we do not have these types of conflicts.
If we reverse our assumptions and make A’s desires fixed, while B’s desires are malleable, then we have reason to condemn and criticize those who become B-like agents for acquiring desires that tend to thwart other desires. In this way, we can prevent B-like agents from coming into existence, and thus avoid the problem entirely.
If all of the relevant desires are malleable, then we can bring other issues into the equation to determine which we should promote and which we should discourage. Do any of the desires tend to fulfill other desires (e.g., a desire to exercise that preserves an agent’s ability to fulfill other desires)? Which desires can be easily molded, and which require a great deal of effort? Instead of weakening or strengthening a desire, can we change its shape by adding exceptions and qualifications?
If C is a desire utilitarian, as Kmeson says, then he is not going to be looking for the act that tends to fulfill the more and stronger desires. He is going to be looking at the desires themselves, trying to reduce the incidents of desires that can only be fulfilled by thwarting the desires of others. He is going to be looking to prevent this type of situation from even coming into existence my molding the malleable desires that people have.