Where morality lives

How should neuroscience change philosophy?

By Joshua Rothman
April 24, 2011

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What is morality? For millennia, the problem has bedeviled philosophers, who have debated whether it’s divinely inspired, instinctual, or an abstract set of rules that we should figure out rationally. Patricia Churchland, a philosopher at the University of California San Diego, thinks it’s time for a different kind of answer: Understanding morality, she argues, means understanding its roots in the brain.

Churchland, a former MacArthur “genius” fellow, has built a career trying to knit together neuroscience and philosophy, two fields that usually prefer competition to cooperation. In her new book, “Braintrust: What Neuroscience Tells Us about Morality,” Churchland aims to combine the explanatory power of science with the caution and clarity of philosophy. She starts by explaining what’s most clearly known about how morality works in the brain. We know, she argues, that human moral behavior is rooted in the brain’s “circuitry for caring”—ancient biological circuitry that we share with other mammals. (When wolves care about their offspring, what happens in their brains and bodies is remarkably similar to what happens in ours.) Most mammals care only about themselves and their children. In human beings, though, the circle of caring extends widely, even to strangers.

These broad circles of caring are the foundations, Churchland says, for morality. They create the tensions that are the essence of moral life. Tension is inevitable, because caring broadly raises challenging, practical problems: All those competing moral obligations need to be balanced out. Churchland argues that we solve those problems the same way we solve other practical problems: sometimes instinctually, but also by drawing on our learning, reasoning, and culture. In the end, her picture of morality recalls Hume’s, or even Aristotle’s: Aristotle, she writes, knew that morality had its roots in human nature, but he also recognized moral problems as “difficult, practical problems emerging from living a social life.” In this conception, morality is rooted in our instincts, but it isn’t entirely instinctual.

Churchland believes that this view of morality is “liberating.” As moral beings, we neither slavishly follow our instincts, nor subordinate our emotions to disembodied rules. Instead, we draw on resources from the full span of our human nature in an effort to care about one another.

Churchland spoke to Ideas from her home in San Diego.

IDEAS: What convinced you that, as a philosophical thinker, you needed to learn about the brain?

CHURCHLAND: My first book, “Neurophilosophy,” came out in 1986. [At that time,] I’d really become disillusioned with mainstream philosophy, because it didn’t seem to be really interested in making progress. It wasn’t interested in empirical data....People were saying that we could understand the nature of the mind without understanding the nature of the brain—and that seemed to me to be very wrongheaded! And so, much to the disgust of many of my friends in the field, I went to medical school to learn neuroscience.

IDEAS: So what does morality have to do with the brain, exactly?

CHURCHLAND: The evolution of the mammalian brain initially allowed for the expansion of caring, beyond just caring for one’s own survival and well-being, to the survival and well-being of offspring. That required very special circuitry, different from the circuitry you might see in a lizard or a frog...and it also involves an enhanced capacity for learning. [In evolution,] there’s a trade-off between being prepared, when you’re born, to be independent—as, say, a turtle or a lizard is—and being able to learn a lot. Mammals are born very helpless and dependent. But they can learn about their environment; they’re much more adaptable, much more flexible. And they can learn from their social environments....And then, as the brain expands even more, we see an increase in the sophistication of problem solving. Where those problems are social problems, we see much more subtle and sophisticated ways of handling things.

IDEAS: Do other mammals have moral lives, too?

CHURCHLAND: In a way it’s kind of a semantic issue: Some people feel that part of what the word “morality” means is something reserved for those within our species. But I like to think that, because of the shared biology and shared evolutionary history of the human brain, different species have a morality, a way of handling their social business, that is suited to that species.

IDEAS: But to most people, morality is about more than “handling social business”—it’s about right and wrong.

CHURCHLAND: That opens a really interesting question about differences in moral practices across cultures and across time....[Take] Inuit culture and how different it is from, say, the culture of people living on the Hawaiian Islands. It really reflects their ecology and their history, their way of making a living....The Inuits, for example, at least until they were “Europeanized,” had to practice infanticide. And it wasn’t uncommon, when people got old and decrepit and could no longer participate in the hunt, [for them] to wander off onto the ice floes and bid farewell to the group. We may think of that as being unacceptable, but that’s because we live in a remarkably prosperous culture....I would never think of the Inuit practices in the 19th century as “wrong.”

IDEAS: But isn’t that exactly why some philosophers search for moral rules for standards to live up to, axioms that make you look beyond practical life as you understand it?

CHURCHLAND: The problem with thinking it’s all rule-bound is that philosophers have not been able to come up with acceptable, unexceptionless rules. Anything you can come up with is obviously flawed. [That said,] many social, moral problems are problems to which there is no intuitive answer. We just have to come together and negotiate and figure it out. And these are problems, often, that arise in very complex situations....The Inuits in the 19th century would never face the question, “Under what conditions are you obliged to donate a kidney to a stranger?” But that’s a question for us.

IDEAS: How does thinking of morality as rooted in the brain change the experience of moral life?

CHURCHLAND: I would like to think that it will ripple out and have humanizing effects. In our lifetime, one instance of this has been the change that came about in people’s attitudes, at least young people’s attitudes, as a result of the discovery that there were really differences in the brain, and probably differences in the infant brain, between people who were going to be homosexual in their orientation, and people who were not.... All kinds of people said, “What a relief! It’s not a character flaw!”....Many people thought: Why are we doing these horrible things to people who are gay? It rippled out.

IDEAS: Why is knowing that morality’s based in the brain liberating or humanizing? Some people would say the opposite: That tying morality to the brain is limiting.

CHURCHLAND: It’s liberating because it’s an explanation of why, for so many people, there is a commonality—why there can be a meeting of minds, why they can connect and feel the kindness and generosity and welcomingness of people who are so very different in their cultural practices....And it also helps explain those very differences in cultural practices....You come to see that the brain is very, very sensitive, as it grows up, to the demands of the social world, and that conscience is built from those demands; intuitions are formed and made from social pressures....We’re living in a connected world; we need to understand these [differences], and to resist ideological fanaticism, whether it’s within our own culture or within other cultures.

Joshua Rothman is a graduate student and teaching fellow in the Harvard English department and an instructor in public policy at the Harvard Kennedy School of Government. He teaches novels and political writing.