In my defense of desire utilitarianism I sometimes use an imaginary case of a parent given two options by a captor. One option is that the parent's child will be tortured mercilessly while the parent will be lead to believe that the child is living a healthy and happy life. The other option is that the child will be given a healthy and happy life while the parent will be made to believe that the child is being tortured mercilessly.
A great many people claim that they would choose the option where they falsely believe that their child is being mercilessly tortured, while the child is in fact living a healthy and happy life. I use this to argue that people do not make choices based on what will make themselves happier.
Instead, I argue that a 'desire that P' motivates an agent to choose those options that will generate states of affairs in which P is made or kept true. In this case, the desire that one's child be healthy and happy motivates parents where that desire is sufficiently strong to choose the option in which the proposition, "My child is healthy and happy," is true.
Carrier makes a move in place of this that the parent is instead choosing to be a particular kind of person.
The mother has a choice really not between two fates for the child, but between two fates for herself: will she become (in her moment of deciding) the sort of woman who would choose Option 1 or the sort of woman who would choose Option 2?
First, what does it mean to be "the sort of woman who would choose Option 2"? In one sense, this sounds a lot like the case of a person who makes a carefully detailed and precise plan to perform a spontaneous action.
The type of person the person in this example should be is the type who chooses the welfare of her child without thinking about being any sort of woman. The "type of person" that I am talking about is one who, given a choice between an option in which her child is mercilessly tortured versus one in which the child is left to live a healthy and happy life will choose the latter without a single thought to the question, "What type of person do I want to be?".
The person who is more concerned with the well-being of her character and not the well-being of her child (except insofar as the child is a means of displaying or acting like a person of good character) has already taken severe demerits with respect to the quality of her character.
Second, what make one ‘type of person’ better than another anyway? One person might want to be the type of person who would do anything for the welfare of her child. Another might want to be the type of person who is the autocratic ruler of as much land and as many people as he can get control over. Another might admire the character of Jack the Ripper, or to be the leader of his own personal cult where sheepish followers allow him to use them to fulfill whatever desires he has without protest or complaint.
If I am trying to choose what type of person I want to be, how do I weigh the options? And what justifies the choice?
If these options are going to be evaluated in terms of maximizing happiness, then I have to ask why happiness has value, and nothing else. This returns to a long-standing question that I have had against happiness theories – what is it that gives happiness value and nothing else?
Desire fulfillment theory does not give value to only one thing. Rather, it holds that a desire that P is a reason for action that exists to realize a state of affairs in which P is true. A desire to be happy would be a mental state that would motivate an agent to act to realize a state of affairs in which, "I am happy" is true.
So, desire fulfillment theory can answer the question of why happiness has value – because people have a desire for happiness. However, there is no reason to believe that happiness is the only thing a person is capable of desiring. Not only are they capable of desiring other things, they do desire other things. In fact, the realm of possible desires is as varied as the realm of possible beliefs. If a person can believe that Q, then he can desire that Q for any Q.
So, if we are not going to use desire fulfillment to account for the value of happiness, how are we going to account for it? And how are we going to exclude everything else?