I have cause, recently, to return to reading more academic philosophy on the issues that interest me.
In that reading, I have come across the following:
Heathwood, Chris, Desire-Based Theories of Reasons, Pleasure, and Welfare Oxford Studies in Metaethics 6 (2011): 79–106.
I hold that value-based reasons do not exist. Desires provide the only end-reasons for intentional action.
This article concerns "normative reasons" - the types of reasons that justify an action. One can admit that a desire to inflict harm on another is a motivating reason, but it is not a normative reason. That is to say, it is not the type of reason that makes inflicting harm on another person a good thing to do. One could argue that normative reasons require value-based reasons.
Chris Heathwood provides two arguments in favor of value-based reasons in this article.
The first argument is the "Argument from Arbitrariness".
It goes as follows:
[D]esires can provide reasons. But if some desire is the ultimate basis for some reason, then there can be no reason for having this desire. If there were, then the desire wouldn’t be the ultimate basis for the reason. Whatever supplied the reason for having the desire would be more fundamental. But if there is no reason for having the desire, then the desire is arbitrary. . . . But, the argument claims, it can’t work that way. Arbitrariness is anathema to reasons. If a “reason” is based ultimately on an arbitrary state – a state we have no reason to be in – it can’t be a real reason after all. Why should we follow the direction of some desire, when that desire is itself without any justification? How could such a desire have any legitimate authority?I would argue that you can't prove that something exists by arguing that we have built a claim of its existence into the meanings of our terms.
Our fundamental desires - from our basic desire for pleasure and aversion to pain to the desire for sex to our tastes for food - are all molded by evolution. They are determined by the way our brains have evolved, and the way our brains have evolved is determined in part by random chance (genetic mutation) and contingent facts (the environment in which those random variations occurred). They are, in an important way, arbitrary. That is simply the fact of the matter.
Heathwood expresses his argument another way:
Here is a way to illustrate the point. A says to B, “What reason is there for you to do X?” B replies, “Doing X will lead to Y, and I want Y to occur.” A inquires further, “Why do you want Y to occur?” B continues in the same vein: “Because Y will lead to Z, and I want Z to occur.” A won’t let it go: “What reason is there to want Z to occur?” B’s chain of desire must eventually stop of course, presumably in some intrinsic desire, or desire for something for its own sake rather than for what it leads to. Let’s suppose that B intrinsically desires that Z occur. In response to A’s question, “What reason is there to want Z to occur?”, B thus replies, “Well, Z won’t lead to anything else I want; I just want Z to occur, for its own sake.” But A can reasonably ask, “Ok, but why? Why want Z to occur for its own sake?”The answer to "Why want Z to occur of its own sake" is "because evolutionary and environmental influence have made me such that I want Z to occur for its own sake. I have evolved to have a desire for pleasure, and an aversion to pain, a desire for sex, a preference for certain food types, an environment with a preferred temperature, the company of others, and the like."
We can still see the force of the argument that this certainly cannot justify behavior. If we evolved a disposition to murder neighboring and competing tribes and take their resources, or to commit rape, that would not justify those actions.
However, we do not need to introduce value-based reasons to bring in the subject of justification.
Epistemologists have faced a similar problem. When it comes to justifying a belief, it can be justified by showing that it follows logically from one or more premises. Those premises, in turn, can be justified only by appeal to prior premises. At some point, we are either going to have to reach some self-justified premises, or this chain will go on forever.
In epistemology, some thinkers have adopted a position called "coherentism". On this view, a belief is justified in virtue of the strength and number of its connections to other beliefs, which are justified in terms of the strength and number of their connections. There are no fundamental self-justifying beliefs.
Similarly, desires can be justified in virtue of the strength and number of their connections to other desires. We would look at the tendency of a desire to fulfill or thwart other desires, and use the strength and number of those connections to determine the merit of each individual desire. Desires that tend to fulfill other desires would be "justified" in the normative sense - they would count as providing reasons that people have (desire-based) reasons to endorse. Desires that tend to thwart other desires would be desires that others have reason to condemn (such as the desires contributing to tribal warfare and rape mentioned above).
But, the main problem with value-based reasons is that you can't prove their existence by writing an assumption that they exist into the meanings of our terms - any more than you can prove the existence of God by saying that it is a part of the meaning of the term "God" that it must exist. One needs a different type of argument to prove existence, and there is no evidence that value-based reasons exist.