The right act is the act that a person with good desires would have performed.
Good desires, in turn, are desires that tend to fulfill other desires. For an account of how desires can be evaluated, and the sense in which agents can have motivating reasons to promote and inhibit desires, please see A Harmony of Desires
I am going to defend these propositions in a series of posts where I hope to show how well it explains a number of elements of morality; including such things as negligence, non-obligatory permissions, and moral dilemmas.
Here, I am going to discuss the moral concept of the “bad Samaritan”
The problem of the Bad Samaritan represents another problem (in addition to negligence and recklessness) for theories that base the morality of an action on the morality of the desires that motivate that action.
In the case of the bad Samaritan, a person performs a right action, but does so for reasons that would consider bad.
Imagine a person who wants nothing more than to see his brother suffer. He discovers that his brother has raped and murdered some children. Therefore, for the sole purpose of causing his brother grief, he turns his brother into the authorities.
For the sake of this example, we are assuming that the agent in this case cares nothing about saving children from being raped and tortured. He is entirely indifferent to the plight of the children and, if not for the fact that this is an effective way to harm his brother, he would act against his brother. In fact, let’s go so far as to say that the agent in this case knows of other people who have raped and murdered children. Only, he does not turn them in to the authorities because he does not wish to.
If it were the case that right action was determined by the value of the desires that motivated them, then we would have a moral rule that states, “If your dominant reason for reporting somebody who rapes and murders children to the authorities is your want to do harm to that person, then you should keep quiet about those rapes and murders.”
However, we have no such principle. We hold that the agent has an obligation to report the person who rapes and murders children in to the authorities even if he does so for a bad reason. We would prefer it (and we have many strong reasons to prefer it) to be the case that the agent works out of concern for the children and respect for the law. However, the rightness of the action does not demand that this criteria be met.
The principle that the right act is the act that a person with good desires would have performed is consistent with the idea of this agent having the right to report his brother to the authorities, even if he does so for no good reason.
It is still the act that the person with good desires would have performed.
This is not to say that desire utilitarianism classifies the agent a good person. Quite the opposite. A good person is actually a person with good desires. The Bad Samaritan is truly a bad person. Yet, even as a bad person, in this one case, he does the act that a person with good desires would have performed.