You do not reason with evil. You condemn it.
A member of the studio audience described a point of dispute between Richard Carrier and myself as follows:
I think the much more interesting debate is Carrier's position that no fully-informed agent would ever have desires that people have reasons to inhibit (like a desire to steal, or to rape). I don't understand how this could possibly be the case. It seems somewhat naive. It also implies that anyone can be reasoned into doing what is right with enough argumentation, whereas DU explicitly states that this is impossible.
Without getting into whether this is an accurate characterization of Carrier’s views, I would like to be a bit more precise in what desire utilitarianism (aka desirism) explicitly states.
The proposition, “Anyone can be reasoned into doing what is right with enough argumentation” is false.
Anyone can be reasoned into doing that which would fulfill the most and strongest of current desires. However, what fulfills current desires is not necessarily the same thing as what is right.
The role of reason in the brain of a child rapist is to make a plan that would result in fulfilling the desire to rape a child while putting at risk the least and weakest of the agent’s other desires. This plan may include joining the priesthood or becoming a public school teacher or marrying the insecure co-worker with an attractive daughter from a previous marriage.
The role of reason in the brain of an alcoholic is to create a plan to get drunk. Recall that reason seeks to fulfill current desires. There is no backwards causation that allows future desires to have any impact on current actions except through a current desire that future desires be fulfilled. Unfortunately, alcohol tends to interfere with the capacities of reason and cause an agent to make very poor plans for preventing the thwarting of other desires.
Reason works great on those people who have good desires. The role of reason in the brain of a good person is to create a plan for fulfilling the most and strongest of those desires – desires that tend to fulfill other desires.
The role of reason in the brain of a devoted parent is to make plans to secure the current and future well-being of her children. That plan may include parent-child activities, a visit to a museum or a zoo, placing limits on the junk a child watches on television, and warning the child against activities that would put the child’s future well-being at risk.
If we see such a person planning a course of action that threatens the child’s future well-being, a healthy dose of reason can put her on the right course. If, for example, she creates a plan to prevent her child from being immunized against swine flu or hpv virus, a dose of reason can cause her to see the error in her ways and to change her plan.
However, in the same way that reason can help the devoted parent revise her plan for securing the future well-being of her child, it can help the child rapist to make a better plan for raping a child or help the alcoholic to make a better plan for getting a drink.
There are two steps we can take to get such people to do the right thing, and reasoning with them is not one of them.
Since they are making plans to fulfill the most and strongest of their current desires without thwarting other desires, we can influence their plans by threatening to thwart those other desires. We put efforts into inflicting harm on people who make and execute those types of plans, so that their plans must include either the costs of detection or the cost of avoidance. We increase the penalties against drunk driving, and we put more of an effort into capturing people whose plans include driving while drunk.
Or we can alter the desires themselves, reducing the strength and prevalence of those desires that result in these types of plans through public condemnation. We also have the option of putting conflicting desires in the way of bad desires so that, even if a person has a desire to drink, he has an even stronger aversion to (the possible effects of) driving while drunk that causes him to make plans that avoid this activity. We do this by praising, and thus strengthening, desires that would inhibit plans that would thwart other desires.
Threatening people and increasing activities that aim at identifying those who make and try to execute evil plans is not an act of reason. It is, if we are honest, an act of violence (or a threatened act of violence that we will make good on if the right conditions are met).
We do not alter a person’s desires by reason. The relationship between praise and condemnation on the one hand and the desires of agents on the other is not one of implication. It is one of causation. It is not a relationship of reason – any more than the relationship between electricity and magnetism is a relationship of reason. It is a relationship of natural law – a relationship that we can use to improve our lives if we understand it well enough.
It is because of this that I argue that atheists need to get into the habit of praising virtue and condemning vice. It is not enough to show that reason proves or disproves certain claims. It is also necessary to condemn those who are intellectually reckless, as we would condemn the drunk driver, whose desires prove a willingness to make plans that threaten the safety and well-being of others.
This is where I disagree with the methods of the accomodationists, who think that disinterested reason can bring about virtue. It cannot. Praise and condemnation are the tools for realizing those ends – not reason.