Joshua May's new book Regard for Reason in the Moral Mind (Oxford University Press) argues, on the contrary, that the scientific research in moral psychology that I cite actually does not sustain Hume's sentimentalist ethics, because it supports an anti-Humean rationalism in moral philosophy. Hume is famous for declaring: "Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them" (Treatise of Human Nature, 18.104.22.168). May claims, however, that there is nothing in the empirical science of moral psychology that refutes the anti-Humean position "that normative beliefs can causally produce a normal, non-pathological action without merely serving or furthering an antecedent desire. On this picture, we can be motivated to act ultimately by recognizing that it's the right thing to do. Reason is not a slave to such passions" (179).
I agree with May in rejecting pure sentimentalism (like that promoted by Jesse Prinz), because this ignores the fact that while our emotions or desires motivate our actions, those emotions or desires are prompted and directed by our rational judgment, and thus emotion alone cannot explain our moral actions.
I also agree with May in rejecting pure rationalism (like that of Immanuel Kant), because while reason influences our conduct, pure reason alone cannot move us to act without the motivational impetus of emotion or desire. Although May does not emphasize or elaborate the point, he clearly rejects the Kantian position that "we can arrive at moral judgments by pure reason alone, absent any sentiments or feelings" (5, 19, 97, 186-87).
What we need, then, is a theory that accounts for the experimental research on moral judgment that shows a complex interaction of reason and emotion. The best statement of such a theory is Hume's rationalist sentimentalism. As I indicated in my previous post on Jonathan Haidt, Hume is often mistakenly identified as an irrationalist emotivist. When Hume declared that "reason is, and ought only to be the slave of the passions," he was not denying the power of reason in moral judgment. As the context of this remark makes clear, he believed that reason can direct action but not motivate it: "The impulse arises not from reason, but is only directed by it" (1888, 414). When our passions are accompanied by false judgments, reason can properly correct them: "The moment we perceive the falsehood of any supposition, or the insufficiency of any means, our passions yield to our reason" (1888, 416). "Reason and judgment may, indeed, be the mediate cause of an action, by prompting, or by directing a passion" (1888, 462). Consequently, "reason and sentiment concur in almost all moral determinations and conclusions" (1902, 172). For example, reason might instruct us as to how justice could be useful to society, but this alone would not produce any moral approbation for justice unless we felt a sentiment of concern for the happiness of society (1902, 285-87).
Consider, for example, the research by Joshua Greene (2013) and others who have used functional MRI to scan the brains of people as they make decisions about the Trolley Dilemma. In the Switch Case, most people are willing to pull the switch to save five lives while taking one life. But in the Footbridge Case, most people are unwilling to push the fat man onto the tracks to save five lives. In judging the Switch Case, the more calculating parts of the brain are activated (including the dorsolateral prefrontal cortex), while in judging the Footbridge Case, the more emotional areas of the brain are active (including the ventromedial prefrontal cortex).
Like many of the thought experiments favored by contemporary philosophers, this Trolley Dilemma is a cartoon story that doesn't seem realistic. But we could also think about some real cases in history--particularly the history of war--that would present essentially the same dilemma, which comes up in the debates over "just war" reasoning. As I have indicated in a previous post (here), Winston Churchill and the British war leaders faced a real Trolley Dilemma in responding to Germany's flying bomb attacks on London in the summer of 1944. The British philosopher who first proposed the Trolley Dilemma--Philippa Foot--lived through these attacks.
Here's Jesse Prinz's interpretation of how people judge the Trolley Dilemma:
"In all these moral dilemmas, there are too options: you can save five people (that's good!), or you can do something that results in one person dying (that's bad!). When you think about doing something good, you may have a positive emotional response; it feels good to help people. When you think about doing something bad, your response is negative. These two emotional forces battle it out in the brain and the stronger one wins." (2012, 297)Prinz is silent, however, about the point made by Greene and his colleagues that there is no absolute separation between reason and emotion in the brain. For example, the dorsolateral prefrontal cortex and the ventromedial prefrontal cortex are interconnected, and this confirms Hume insight about the interconnectedness of reason and emotion in moral judgment.
Prinz is also silent about the point made by John Mikhail that the emotional responses to the Trolley Dilemma show an intuitive grasp of the rational principle of double effect, which often figures prominently in just war reasoning. Mikhail generalizes this principle to cover homicide and battery: "the principle holds that an otherwise prohibited action, such as battery or homicide, which has both good and bad effects may be permissible if the prohibited act itself is not directly intended, the good but not the bad effects are directly intended, the good effects outweigh the bad effects, and no morally preferable alternative is available" (2011, 149).
Most people think pushing the fat man is wrong because their emotional response against this embodies a rational principle by which a directly intended killing of an innocent person is wrong, while an indirect and unintended killing of an innocent person might be justifiable if it achieves a good effect that outweighs the bad effect.
But May rightly observes that this is mistaken, because "integral emotions can alert us to morally relevant factors, so it's not problematic in general to base one's belief on them" (99). Our emotional aversion to pushing the man off the footbridge to stop the trolley from killing the five people is alerting us to "something like greater agential involvement in the generation of a bad outcome." As opposed to the Switch case, we are here "harming another actively, purposefully, and in a personal way," which is surely a morally relevant factor (100-101).
But if May sees here the necessary combination of reason and emotion or beliefs and desires in explaining moral action, which is necessary because pure thought by itself cannot motivate us to act without emotion or desire, then it seems that May is actually agreeing with the Humeans in embracing a rationalist sentimentalism.
May nonetheless insists that while he agrees with the Humeans about the need for combining reason and desire, he disagrees about which comes first: the Humean thinks that reason leads to moral action only when it is guided by an antecedent desire, while the anti-Humean thinks that moral reasoning that is not guided by any antecedent desire can produce a desire that motivates the execution of the moral judgment reached by reason alone. Unlike the Kantian anti-Humean who thinks that moral reason produces moral action without any need for intrinsic desire, May's anti-Humean thinks that moral reason produces the intrinsic desire that then produces the moral action dictated by reason, and thus reason is the ruler of desire, not the slave. Thus, May can say that "reason is not a slave to unreasoned desire," because moral reason creates its own reasoned desire to motivate moral action (188).
How exactly does this happen? May explains: "The process involves ordinary causation: an intrinsic desire is causally generated by a normative belief and the relevant disposition," because "it's partly constitutive of being a rational, virtuous, or strong-willed person that one possesses the disposition to desire in accordance with one's normative beliefs." Notice that May has added a reference to "disposition." He concedes that "Humeans must say something quite similar. The only difference is that, instead of a disposition, Humeans posit a full-blown desire," because they believe that "actions are generated by intrinsic desires combined with beliefs about how to satisfy them" (190-91).
The Humeans might complain that May's "disposition" is just another word for desire, so we might as well say that reason is the slave of the dispositions!
". . . the best anti-Humean theory merely posits a disposition for normative beliefs to generate the corresponding desires. While a strong-willed person, for example, may lack the antecedent desire to throw her pack of cigarettes away, she may simply have a disposition to do so if she believes it's best to trash them."
"Humeans may be tempted to count such dispositions as desires and declare victory. However, while we're working with a rather broad conception of desire, we shouldn't broaden it to any mere disposition of a person to do something. A desire is a goal-directed, conative, motivation-encompassing state with some content, so it's a state whose function is to bring about what's desired. But desire is not the sole proprietor of dispositions relevant to action. To adapt an example from Darwall . . ., even if I'm disposed to eat a piece of pie upon seeing one, this disposition alone need not constitute a desire for some pie. A mere disposition can graduate to a full-fledged desire only if it has the requisite function and content . . . . Of course, Humeans would explain the eating of some pie in terms of an antecedent desire to eat delicious food when it's available. However, the pie example is not meant to refute Humeanism but rather to show that being disposed toward some action (e.g., eating pie) doesn't entail antecedently desiring it in particular" (189).Here May's distinction between disposition and desire seems to be a distinction between a general desire (such as a desire for delicious food) and a particular desire (such as a desire for this piece of pie before me that I judge to be delicious food), where the transition from one to the other requires a rational judgment. This looks like what Aristotle identified as the "practical syllogism" in The Movement of Animals: the major premise is a desire for something, the minor premise is a judgment that some action will satisfy that desire, and the conclusion is the execution of the action. So if I desire healthy food, and if I judge that this piece of pie before me is healthy food, then I will eat it. May's argument seems to be that my desire to eat this piece of pie is not antecedent to my judgment that this is a good piece of pie. Rather, my rational judgment that this piece of pie is healthy food appeals to my general disposition to eat healthy food in a way that produces the desire to eat this piece of pie. But, still, the Humean will say that my rational judgment here is serving my general disposition, which might as well be called a desire.
Since May admits that reason must be combined with a motivating disposition to create a new desire, which then motivates action, it's hard to see that this really differs from the Humean claim that all action requires the combination of reason and an antecedent desire. May even admits the weakness of his argument:
"Now, I don't pretend to have conclusively ruled out Humeanism as a hypothesis about the structure of motivation. I only aim to show that moral beliefs play an important role in human action and that we lack empirical reason to always posit antecedent desires that they serve or further. Perhaps our best theory will require always positing such antecedent desires. As we saw in the previous chapter, construing moral integrity as involving such antecedent desires isn't always incompatible with virtue anyway" (198).It's not clear to me how any neuroscientific experiments could resolve this dispute between May's "sophisticated anti-Humeanism" and the Humeans. The scientific research can refute both pure emotivism and pure rationalism by showing that neither emotion alone nor reason alone can explain our moral psychology, because, as May says, "both reasoning and emotion together play important roles in moral psychology." But it's hard for scientific research to decide whether reason is prior to emotion or emotion is prior to reason, because once one recognizes the cognitive aspects of emotions as resting on judgments about the world, the line between emotion and reason becomes fuzzy. May says that "the reason/emotion dichotomy, intuitive as it may be, is either spurious or fruitless" (228). A Humean like Haidt says the same thing in speaking of the "useless dichotomy between cognition and emotion." "Emotions are not dumb. . . . Emotions are a kind of information processing" (Haidt 2012, 44-48).
Any experimental testing to resolve this dispute between May and the Humeans would require some agreement on possible scenarios that could be studied. The anti-Humean Stephen Darwall has offered one good example of what he interprets as an illustration of how moral judgment creates a new desire to execute the judgment without any need for an antecedent desire. The Humean Neil Sinhababu (2009) accepts this as a good example for study, but he points to evidence that there really is an antecedent desire in the story. Although May accepts Darwall's argument and rejects Sinhababu's argument, May does not speak about this story.
Here's the story:
"Roberta grows up comfortably in a small town. The newspapers she reads, what she sees on television, what she learns in school, and what she hears in conversation with family and friends present her with a congenial view of the world and her place in it. She is aware in a vague way that there is poverty and suffering somewhere, but sees no relation between it and her own life. On going to a university she sees a film that vividly presents the plight of textile workers in the southern United States: the high incidence of brown lung, low wages, and long history of employers undermining attempts of workers to organize a union, both violently and through other extralegal means. Roberta is shocked and dismayed by the suffering she sees. After the film there is a discussion of what the students might do to help alleviate the situation. It is suggested that they might actively work in promoting a boycott of the goods of one company that has been particularly flagrant in its illegal attempts to destroy the union. She decides to donate a few hours a week to distributing leaflets at local stores." (Darwall 1983, 39; Sinhababu 2009, 483-84)According to Darwall, this shows that Roberta's decision to support the boycott arose from her moral judgment that the workers were suffering from unjust exploitation, which created the desire that these workers not suffer, and this new desire then motivated her to act in accordance with her moral reasoning. Contrary to what the Humeans would say, there was no antecedent desire guiding her moral reasoning, but instead her moral reasoning created a new desire to motivate her moral action: her passions were the slave of her reason.
But why, Sinhababu asks, is Roberta "shocked and dismayed by the suffering she sees"? Aren't those emotions of shock and dismay evidence of an antecedent desire that human beings should not suffer unfairly? This general desire that people not suffer could then be turned into the particular desire that the workers in the South should be relieved from their suffering once she understood the film's presentation of the information about their suffering. So here her moral desires guided her moral reasonng to moral action. Her desire that humans not suffer was latent in her mind until it was activated by the judgment that people were suffering in the South.
What would be May's alternative explanation? Would he say that Roberta had an antecedent disposition that human beings not suffer, but this was not an antecedent desire? Or would he say that Roberta's moral reasoning about the suffering of the Southern workers created a disposition that humans not suffer that could then produce a desire that these Southern workers should not suffer?
Could this be experimentally tested? We could test some subjects for the desire that people not suffer. We could then show them the film about the Southern workers. We could then see if the desire to relieve the suffering of the Southern workers arises in those subjects who had no antecedent desire that people not suffer. Of course, we might expect that almost everyone would have some general desire that people not suffer.
If we were to scan their brains during the test, I am not sure that we could distinguish reason and desire clearly enough to resolve the debate between May and Sinhababu.
Darwall, Stephen. 1983. Impartial Reason. Ithaca, NY: Cornell University Press.
Greene, Joshua. 2013. Moral Tribes: Emotion, Reason, and the Gap Between Us and Them. New York: Penguin Press.
Haidt, Jonathan. 2012. The Righteous Mind: Why Good People Are Divided by Politics and Religion. New York: Pantheon.
Hume, David. 1888. A Treatise of Human Nature. Ed. L. A. Selby-Bigge. Oxford: Oxford University Press.
Hume, David. 1902. Enquiries Concerning the Human Understanding and Concerning the Principles of Morals. 2nd ed. Oxford: Clarendon Press.
May, Joshua. 2018. Regard for Reason in the Moral Mind. Oxford: Oxford University Press.
Mikhail, John. 2011. Elements of Moral Cognition: Rawls' Linguistic Analogy and the Cognitive Science of Moral and Legal Judgment. New York: Cambridge University Press.
Prinz, Jesse. 2012. Beyond Human Nature: How Culture and Experience Shape the Human Mind. New York: Norton.
Sinhababu, Neil. 2009. "The Humean Theory of Motivation Reformulated and Defended." Philosophical Review 118:465-500.