Studying Morality through Brain Scans

I have a question from the studio audience regarding the relevance of scientific brain research on morality. Specifically, when scientists do brain research, such as when they put people into MRIs and ask them questions or to make choices in order to determine how the brain functions in these circumstances, what does this say about morality?

Actually, it says absolutely nothing.

Imagine putting an astronomer into a cat scan and asking him all sorts of questions about black holes or quasars. You get an image that tells you what parts of the brain were active at the time and the sequence of neural findings.

However, when you do this, you learn absolutely nothing about black holes.

It is quite bizarre for somebody to be conducting these types of experiments – doing brain studies of astronomers while they think about astronomical concepts, and for the researcher to be claiming that he, too, is an astronomer. Measuring brain states of astronomers thinking about astronomical concepts is not, itself, astronomy.

In particular, while the brain researcher can get a clue as to how the astronomer thinks about black holes, he cannot infer from his brain scans which of those propositions are actually correct. He can get an image of Stephen Hawking’s brain while Hawkins thinks about evaporating black holes. However, he cannot use his brain scans as proof that black holes do, in fact, evaporate.

Measuring brain states of people while they think about moral concepts is not, itself, ethics (or moral philosophy). The scientist is measuring what is going on in the brain. In doing so, he can get an image of what happens when an agent concludes that homosexuals should be killed. However, he cannot use his brain scans as proof that homosexuals, in fact, should be killed.

So, how do you ‘test’ desire utilitarianism. How do you prove that desire utilitarianism is true and some other theory is not true?

Desire utilitarianism makes a claim about reasons for action that exist. It says that true value statements are statements about relationships between objects of evaluation and reasons for action that exist, that desires are the only reasons for action that exist, that desires are propositional attitudes – mental states that can be expressed in the form of ‘agent desires that P’ for some proposition P, and that agents act so as to realize states of affairs in which the propositions that are the objects of their desires are true.

Furthermore, because desires are the only reasons for action that exist, the only reasons for action that exist for promoting or inhibiting certain malleable desires exists in virtue of their relationships to other desires. No other reason or action exists for promoting or inhibiting malleable desires.

These propositions are used to explain and predict intentional behavior. If some other theory comes along that does a better job of giving us explanations and predictions of intentional behavior, and that theory postulates reasons for action other than desires, then desire utilitarianism should be rejected in favor of that other theory.

The fact is, whether a person is good or evil, you can get a brain scan of that person’s mental behavior. The idea that you can study ethics by studying brain scans implies that you can look at a brain scan and, from that data alone, make moral judgments.

Take a bunch of brain scans of homosexuals looking at homosexual pornography. Of course there is something going on in their brain when they do this. However, the idea of using scientific research to study ethics suggests that you can look at this data and, knowing nothing else, determine whether homosexuality is moral or immoral.

I would like to know how what part of the brain scan one is supposed to look at in order to determine this morality. What are we going to see in the brain scan of a homosexual looking at homosexual pornography if it is moral that we will not see if it is immoral?

Nothing?

That’s my hypothesis. You can collect all of the brain-scan data you can imagine, and you will still not have any evidence relevant to its moral permissibility or impermissibility.

Take a bunch of brain scans of KKK members while they contemplate the appropriate behavior that whites should have towards blacks. After collecting this stack of brain scans, tell me which part of the brain scan proves the wrongness of racism? What would it take – how would the brain scans of racists be different – if it were the case that racism is permissible.

What about slavery? What difference would we (theoretically) find in the brain scan of slave owners to prove that slavery is wrong? If slavery were not wrong – if those who said that slavery is permissible were correct – how would brain scans of people contemplating slavery be different so as to prove that slavery is morally permissible?

These should be taken as nonsense questions. Indeed, they are. They are nonsense precisely because you cannot study brain scans to get at moral facts any more than you can study brain scans to get at astronomical facts.

Let me use one more example to illustrate a crucial part of this argument.

Imagine a study where research subjects are given a complex mathematical equation to work out in their head. Because of its complexity, people come up with different answers. We take brain scans of all of these people. We even discover that those who get the right answer have different brain processes than those who get the wrong answer, so the researchers can sort the brain scans into two piles – those with feature X, and those without feature X. Let us assume that having feature X corresponds to getting the right answer.

How do we know that this is the right answer?

In order to use this experiment, we have to know what the right answer is before we conduct the experiment. Somebody has to take this complex mathematical equation and actually solve it, using the rules and principles of mathematics, before we can say, “These people got the answer right; those people did not.”

Again, the same applies to morality. We can take brain scans of people who get to the conclusion that homosexuality is immoral. We can take brain scans of people who believe that homosexuality is not immoral. However, before we can determine which if these two groups has the right answer, we first have to do something (comparable to working out the math problem) that tells us what the right answer is.

What are the rules for getting ‘right answers’ to moral questions?

Is there even such a thing as a right answer to moral questions?

Even somebody who says that there are no right answers – that all there is for us to study are the brain scans themselves – is still trapped by the need to prove (separately from the brain scans) that there are no right answers to moral questions. We cannot get that conclusion by looking at the fact that different people undergo slightly different mental processes when they contemplate a moral issue. Certainly, we can take brain scans of people reaching different moral conclusions. However, to decide that neither of them can be right, like deciding that one of them is right and the other wrong, requires looking at something other than the brain scans.

This is also not to say that morality lies outside of the realm of science. The fact that an astronomer cannot study black holes by looking at brain scans of astronomers thinking about black holes does not prove that the study of black holes is subjective. Nor does it prove that the study of the brain scans is not a science. It proves that the study of black holes is not the study of brain scans – that black holes are not to be found in brain scans.

Similarly, the fact that an ethicist cannot study right and wrong by looking at brain scans of people contemplating moral questions does not prove that the study of morality is subjective. Nor does it prove that the study of brain scans is not a science. It proves that the study of morality is not the study of brain scans – that morality is not something to be found in brain scans.

The astronomer needs to actually study (the effects of) these real objects of material so dense that no light can escape them.

The ethicist needs to study actual relationships between states of affairs and reasons for action that exist.