CNN has an article, Can a Molecule Make Us Moral?" that invites me to consider the relationship between desirism and neurobiology.
Simply put, the article reports that levels of oxytocin affects such things as whether an individual is trustworthy or generous.
Does desirism have a problem with that?
The systems for morality are to be found in the brain. If desirism is correct, neuroscientists will discover that behavior is grounded on beliefs and desires, that desires are propositional attitudes, and that agents will act to fulfill the most and strongest of their current desires given their beliefs. It will discover that some desires are malleable, and that the mechanisms for change include reward and punishment. They will also learn the mechanisms for praise and condemnation and that they have the same effect as reward and punishment. All of these will have to do with electrochemical operations in the brain.
My greatest value from working with Luke Muehlhauser is that, unlike me, he had the time and the skill to look at current neuroscience in detail. We found a lot of correspondence between desirism and what neuroscientists were discovering about the brain.
For example, neurobiologists were able to look at the ways experience change an agent's long-term desires. Experience provides rewards and punishments - which have the affect of strengthening or weakening agents' desires.
We did not find a perfect fit.
I had been saying that rewards and punishments modify desires directly. The research seems to be suggesting that the learning effect springs from a difference between expected outcome and actual outcome. Expected rewards or punishments do not modify behavior. Though some of the later research we looked at suggested that current reward independent of expectation still has some role to play.
In developing desirism, I had claimed that the agent does not have to be the one rewarded or punishment for reward or punishment to have an effect on his moral character. The effect is generated by witnessing the reward or punishment - the praise or condemnation - of another person. This provides a role for public criticism and for public praise such as award ceremonies and other honors.
Neurobiologists tell us that we have mirror neurons. These cause us to experience the rewards and punishments of others as if they are our own - which is one of the mechanisms through which social forces mold our moral character.
Even works of fiction from religious parables to children's stories to Star Wars and Lord of the Rings to World of Warcraft and Grand Theft Auto shape our moral characters by making us a witness to the praise and condemnation - the reward and punishment - of others.
If oxytocin promotes generosity and tolerance, the next question to ask is how social forces such as praise and condemnation affect oxytocin.
I do have one long-standing objection to the way biologists approach the relationship between biology and morality. Biologists identify behavior as moral and look for the biological causes of that behavior. However, they gloss over the question, "What is it that makes this behavior moral?"
Higher oxytocin levels may end up being associated with opposition to capital punishment, for example. Does this answer the question of whether capital punishment is wrong? If so, how? How do you get from premises relating biological facts to attitudes about moral issues such as abortion, gay marriage, capital punishment, whether it is okay for 1% of the people to own 50% of the planet - to conclusions about whether these are, in fact, morally right or wrong?
One of the common links biologists draw is that if we are morally opposed to X, then it is wrong. It then looks for the biological underpinnings to our opposition to X and claims to be studying morality. However, this would imply that if we had a disposition to approve of killing all the Jews, then the Jews deserve to die. If we are disposed to enjoy having sex with our stepchildren, then it is morally permissible to do so. Nothing is right or wrong except insofar as a genetic accident makes it so. Alter our biology so that we can enslave others without moral regret, and slavery becomes morally permissible.
And what is the relationship between morality and social tools such as praise and condemnation about? If morality is grounded on some hard-coded biological fact, why praise or condemn others?
Desirism has an answer to the question of relating biology to morality that answers these questions. For moral virtue, we are looking for malleable desires that people have the most and strongest reasons to promote using social forces such as praise and condemnation. An agent may be biologically constituted such that he can kill the Jews without guilt, but this does not change the fact that people generally have many and strong reasons to promote an aversion to that kind of killing.
What makes aversion to such killings a virtue?
Well, people generally have many and strong reasons to promote an aversion to these types of killings using social tools such as praise and condemnation. And moral claims contain elements of praise and condemnation.
What more do you want?