A member of the studio audience sent me a paper in which Paul Thagard wrote that desires are not propositional attitudes.
Thagard, P. (forthcoming). Desires are not propositional attitudes. Dialogue: Canadian Philosophical Review.
I found desire utilitarianism on the idea that beliefs and desires are propositional attitudes. That is to say, they express the agent's attitude towards a particular proposition. A belief that P (a belief that a God exists) is the attitude that the proposition P is true. Whereas a desire that P (a desire that I am eating chocolate cake) is an attitude that P is something that I am moved to make or keep true.
One of the decisions that I made when I was back in graduate school is that I do not have the time to track down all of the different ideas in the philosophy of mind and evaluate which is best. Instead, I decided to employ the view that I would take whatever theory is the received view among those who are engaged in the study of such things.
I fully expect that the belief-desire-intention model that I use will be replaced by better theories over time. When it is, beliefs and desires will either be reducible to terms in this new theory - in which case desire utilitarianism will be reducible as well. Another option is that beliefs and desires will not fit at all in the new theory in which case desire utilitarianism gets discarded as well.
These represent two end points on a continuum. A likely result is that some aspects of belief-desire-intention model will be reducible while others will have to be discarded. This means that desire utilitarianism itself will need to undergo some revisions to fit into the new theory.
I am interested in seeing what direction this research goes.
However, in the mean time, I can take a cursory look at some of the arguments.
One of the arguments that Thagard gives against desires being propositional attitudes is that it makes for awkward sentences. For example, the statement "Andrew desires a beer" does not express an attitude towards a proposition. To turn the statement into one that reflects a propositional attitude it would have to be written in the form, "Andrew desires that he drink a beer."
[T]hese paraphrases are at best awkward, and even more awkward are paraphrases of sentences involving words that dictionaries relate closely to “desire”, such as “want” and “long for”. Only a non-native speaker of English would paraphrase “Andrew wants a beer.” by “Andrew wants that he should have a beer.”
My response to this argument is: So?
There is, or has been, a movement in philosophy that suggests that philosophy look at ordinary language in order to make sense of the world in which we live. However, I have never found any particular merit in that view. Language is an invention - and a rather sloppy invention at that. There is no reason to believe that language is a perfect descriptor of reality such that, if a theory of how the universe is does not fit our language - that it is our theory of how the universe is that must change. Rather, I would argue that it is our language that must change.
If we look at ordinary language, we will find a number of examples in which people speak as if a god exists. Yet, the fact that people make these statements is not proof that a god actually exists. It only serves to show that people believe that such a god exists - a belief that may or may not be true. We do not determine the truth of the matter by looking at whether people speak as if such a being exists.
Similarly, there is no law of language that prohibits people from taking shortcuts with language. There is no reason to require that native speakers use a sentence such as, "Andrew desires that he drink a beer" when native speakers can easily reduce this to a much more manageable phrase, "Andrew wants a beer."
Native speakers can easily figure out the rest.
The real question to answer is not whether the theory best fits our language (with the assumption that if it does not then it is the theory - and not language - that must change). The question to answer is whether the theory provides a way to explain and predict human behavior. The proposition, "Andrew desires that he is drinking a beer" predicts that Andrew will act in such a way so as to make or keep the proposition, "Andrew is drinking a beer," true at least so long as the desire persists.
Does the phrase "Andrew wants a beer" generate predictions that are in any way different from the phrase, "Andrew desires that he is drinking a beer?" If not, then there is no basis on which to say that one phrase represents a better theory than the other. There is no observation that can distinguish the two. The fact that one is an awkward English sentence and the other a common and natural-sounding claim among native English speakers is irrelevant.
I have encountered this objection before, yet I have not encountered it in any context where the person who uses it explains why it is an objection to a theory that it does not conform to plain language.