I want to thank Kevin, a heavily contributing member of the studio audience, for providing me with a statement that I can use to illustrate the bulk of my objections to any type of "moral sense" theory in general, and to the idea of an evolved moral sense in specific.
[O]n introspection, we know that we don't like to suffer. Many, including myself, hold that we have evolved a 'moral sense' akin to the ‘golden rule’ which gives us the ability to sympathize/empathize with others, and therefore, want others to avoid suffering when at all possible
First problem: Some people have acquired a desire to rape and kill children. What justification is there for denying that they, too, have evolved a 'moral sense', that gives them the capacity to rape and kill children when at all possible?
There are those who have an aversion to homosexual relationships. The mere thought of a homosexual relationship causes in them a sense of revulsion. What argument is there against the claim that they have evolved a 'moral sense' against those sex acts that are 'unnatural' that gives them the ability to recognize the wrongness of homosexual relationships and to put obstacles to engaging in those types of relationships whenever possible?
It is not sufficient to answer this question by saying, "Well, if we consider all of the evidence then we can come to see how some of our perceptions are right and some are wrong, in the same way that we can come to see that a straight stick appears bent if it is sticking out of the water."
It is necessary to get beyond this and at least provide an example of this 'considered judgment' in action.
My view is that this 'considered judgment' ultimately takes us to the conclusion that no 'moral sense' exists, that value is a relationship between states of affairs and desires. It is entirely question begging for somebody to assert that we can answer the difficulty I mention above by applying our 'considered judgment' without providing some evidence that this 'considered judgment' actually supports the claim of a “moral sense”.
Second problem: Introducing the concept of a 'moral sense' brings with it a huge amount of conceptual baggage. It includes concepts of duty, obligation, moral prohibition, right, and wrong. Of particular importance is the fact that it imports assumptions about justifications for harming others through fines, imprisonment, and even death. What justification is there for bringing all of this conceptual baggage into the picture.
A person may well be able to argue that we have evolved an aversion to doing harm to others. He may be able to argue that this aversion itself is linked to mirror neurons by which we experience some of the pain that others experience as our own pain.
Actually, I not only hold that a person can argue this. I believe it is true and well supported by empirical research.
However, the leap from this to 'moral sense' is entirely without justification. In fact, it is the very leap from 'is' to 'ought' that Hume warned us about. Hume wrote that in all vulgar systems of morality people begin with all sorts of claims about what is the case, then suddenly jump to claims about what ought to be the case, without explaining how their 'ought' claims can be inferred from the 'is' claims they began with.
The leap from 'aversion to the suffering of others' to 'moral sense' is precisely that – an unjustified and unfounded leap from 'is' to 'ought'.
Third problem: This account of a 'moral sense' faces the same Euthyphro problem that religious ethics has.
Let us assume that we never evolved motor neurons that allowed us to experience the pain of others as our own and, through this, acquire an aversion to the suffering of others. What would this imply?
Would it imply that it is permissible to bring about the suffering of others?
Or would it be the case that causing the suffering of others is still wrong, only it is a wrongness that we lack the ability to sense?
If we go with the first option, then the claim that we have a 'moral sense' is a meaningless tautology. What we sense to be moral, and what is moral in fact, is necessarily the same thing. If we evolved a disposition to kill our step children when we took over a pride, that would be moral. If we evolved a disposition to decapitate our lovers and eat them after sex, that would be moral. If we sensed an interest in slaughtering anybody who belongs to another tribe, that would be moral.
If we go with the second option, we are left with the question, "What is this thing called 'moral' that can exist independent of our ability to sense it? How can we find it? And how can we know that what we 'sense' to be moral is calibrated correctly to what is moral in fact?"
The latter question becomes particularly problematic because evolution would hijack any true moral sense and turn it into a sense of genetic fitness. Unless we assume a remarkable coincidence between genetic fitness and moral value, we must assume that it is likely that at least one state with moral value does not promote genetic fitness.
Fourth problem: People concerned with morality as an institution are not concerned with the harms we cannot do because of some evolved disposition to behave in a particular way. They are concerned with the crimes that, even with our evolved dispositions, are a very real possibility and a very real object of concern.
Allowing that we have some evolved aversion to the suffering of others, it is not nearly as strong as we have reason to want it to be. There are a great many careless accidents (e.g., from drunk driving), lies, thefts, frauds, rapes, assaults, murders, terrorist attacks, political corruption, all forms of tyranny and abuse, holocausts and other attempts at genocide, the slaughter of whole villages, all of them making it plain that whatever aversion to the suffering we may have acquired through evolution is far weaker than we have reason to want it to be.
So, the next questions to come up are, is it possible to cause people to have an even stronger aversion to suffering than nature provided us with and, if so, how? If there is, we certainly have many and strong reason to promote those institutions that would boost this innate desire.
That is what morality is concerned with – not the aversion to suffering that we acquired through evolution, but any additional aversion to suffering that we could acquire as a result of the way we organize our society.
Fifth problem: It makes no sense to hold that people are morally accountable for their genetic makeup. To claim that a person is evil because he has a particular strand of DNA assumes that, somehow, he acquired the choice to determine his DNA. Which is absurd.
Moral concepts are applicable only to those things that involve some element of choice. Which is one of the reasons why I argue that moral concepts are applicable only to malleable desires – desires that are not fixed by nature, but are susceptible to change from social forces.
Ultimately, we are better off abandoning the idea of any kind of moral sense. Our observations are adequately handled by merely postulating an aversion to the suffering of others generated by the firing of mirror neurons. We can also make sense of reasons that exist to promote this aversion to the suffering of others beyond the level that nature provides for us – which is obviously far weaker than we have reason to want it to be. It is this additional aversion, molded through praise and condemnation, that is the concern of morality.