On Desire 2018. Part 30: Explaining Desires

One of Lauria’s three desiderata concerning theories of desires was consonance. (Lauria, Frederico, (2017), “Guise of the Ought-to-Be” In Deonna J. & Lauria F. (eds). The Nature of Desire. Oxford University Press.)

This concerns how well that which the theorist points to in his theory of desires (beliefs that P is good, dispositions to act) fits with the things that desires themselves fit with. This shows the degree of fit between these other things and desires.

Specifically he is concerned with whether that which explains desires also explains that which a theory points to, and whether that which desires explains is also explained by that which a theory points to.

For example, Lauria objects against evaluationist theories that they make the explanation of a desire in terms of an evaluation vacuous, when such claims are not, in fact, vacuous. In other words, a person can make a sensible claim of the form, “I desire D because it has quality Q, and I find Q to be good.” However, if desires are evaluations, then such a statement becomes something like, “I desire Q because I evaluate Q to be good.” This is vacuous since to desire Q is nothing but to evaluate Q to be good.

In short, if desires are evaluations, then evaluations cannot be used to explain desires. Yet, it seems clear that evaluations can be used to explain desires. Thus, desires cannot be evaluations.

I have categorized the theory that I defend as an evaluationist theory. If this is a problem for evaluationist theories, then I must respond to this problem.

Under evaluationism, it would still make sense to say, “I desire D because D contains Q and I desire Q.” This partially explains why one desires D. But why does one desire Q? Perhaps one desires Q because it has some property R and one desires R. This, too, would make sense, if it were true.

However, at some point, the agent is going to end up at something that she desires wholly and for its own sake. At that point, she can do nothing but shrug and say “I just do.”

At this point, where the desire claim is vacuous, the explanation claim is just as vacuous. The agent can say that she desires that P because she holds that P has value. However, she can no more explain why she holds that P has value than she can explain why she desires that P.

Well, actually, she could try to do this if she asserts that value exists as something independent of desire. She could hold, for example, that P has a property of intrinsic prescriptivity and, in virtue of this, she desires it. However, this response is not available to the assignment evaluationist. There is no other type of value other than the value assigned to a state of affairs in virtue of it being an object of desire.

Against the other types of evaluationist who might try this "independent value of P" response, the objection against them is that no such thing exists. Their value claims, though perhaps coherent and linguistically sensible, are nonetheless false.

More specifically, one reaches a point where it is no longer possible to explain why one desires something in virtue of some part or property of a thing. The trail of explanation has reached something wholly and for its own sake. At that point, the only answer to give to the question, “Why do you desire D?” comes fully from an account of evolution (genes), environment (things that happen to agents), and experience (events that activate the reward system). These facts explain both the desire that P and the fact that the agent assigns a measure of importance to “P” being true, which are the same thing.

Assignment evaluationism places root explanations of desires and assignments of value both in the realms of evolution, environment, and experience. When asked why I hate stewed tomatoes, I can point out that this is because evolution formed children to form strong aversions to foods they eat shortly before getting violently ill (a way of getting our biological ancestors to avoid poisonous foods). As a child, I became violently ill after a meal that included stewed tomatoes. Since then, I have had an aversion to even looking at stewed tomatoes.

This story explains my aversion to stewed tomatoes. It also explains why I give a high negative value my eating (or even experiencing by sight or smell) stewed tomatoes. It makes me sick to even imagine such a thing.

The explanations for desires and for assignments of value are the same, providing no reason to reject the thesis that desires are assignments of value. They are assignments, rather than judgments or beliefs, because they come from the agent, and not the object of evaluation.

Before ending, I want to make a note of how this fits into Lauria’s larger argument. Lauria is claiming that evaluative theories of desire make statements that use evaluation to explain desire vacuous, when they are not. Later, Lauria will argue that motivational theories make attempts to explain action in terms of desire vacuous, even though they are not. His own “guise of the ought” theory, he will argue, avoids this problem.

The assignment theory that I am defending says that Lauria’s examples of using an evaluation to explain a desire are cases of using a desire for a part or property to explain a desire for the whole. However, at its foundation, where the desire is for the whole for its own sake, explaining the desire in terms of an evaluation is, in fact, vacuous. The evolutionary, environmental, and experiential history of the creature explains both its desire that P and its assignment if a value to P being true.