Philip Kitcher on Scientific Progress, Ethics, and the Democratic Imagination

Philip Kitcher’s path into philosophy began with what he calls “good advice and a bit of serendipity.” As a math student at Cambridge, he realized he was “getting progressively less interested in mathematics,” until one supervisor told him bluntly that if he continued, he’d “end up like me—I’m only in Cambridge for the music.” That moment set him on a new course. “I decided to do the one-year course in the history and philosophy of science, thinking I’d study the history of astronomy,” he recalls. But then came a fateful encounter with Thomas Kuhn’s The Structure of Scientific Revolutions. “That made me more interested in philosophy,” he says. “The growth of scientific knowledge seemed much more fascinating than any problem I might deal with as a mathematician.”

At Princeton, Kitcher studied with Carl Hempel—known to everyone as Peter—and briefly with Kuhn himself. “Hempel was an absolutely wonderful human being as well as a marvelously clear teacher,” Kitcher recalls. “He gave me a real sense of what it is to understand something very clearly and to work on it rigorously.” Kuhn, though disillusioned with the discipline at the time, left a lasting mark as well. “I learned from him how to think about the history of science,” Kitcher says.

His philosophical range soon broadened dramatically. While teaching at the University of Vermont, a pre-med student once challenged him: why did every example in his philosophy of science class come from physics? “That was a very good criticism,” Kitcher says. “So I went to the library, found David Hull’s Philosophy of Biological Science, and said to myself: this is utterly fascinating.” That discovery led him to Harvard’s Museum of Comparative Zoology, where he spent a sabbatical embedded among biologists like Richard Lewontin, Ernst Mayr, and Stephen Jay Gould. “It was an extraordinary experience,” he says. “A one-year crash course in all sorts of issues in biology.”

That immersion in science deepened his sense of what philosophy could do. “From the very beginning I was interested in cross-disciplinary work,” Kitcher explains. “Philosophers don’t have some special esoteric understanding of the world. What we do is try to take all the various areas of knowledge and the variety with which people live, and fit them together into a larger picture.” He calls this approach synthetic philosophy—the kind of wide learning and integration that he believes marks the great thinkers in history. “Philosophy’s central task,” he says, “is to suggest new ways of looking at things.”

Kitcher’s first major public-facing book, Abusing Science, came about through another twist of chance. “I got the flu,” he laughs. “Sitting in front of the TV, I saw an ad for a book called The Remarkable Birth of Planet Earth. I wrote off for it—it turned out to be a creationist text.” Reading it, he realized most people he knew “would be unable to answer its challenges.” He began giving talks, which soon led to a contract from MIT Press. “It was a bit too uncharitable to creationists as people,” he reflects now, “but as thinkers, they deserved criticism.” The book became a touchstone in debates over evolution and science education.

His next work, Vaulting Ambition, took aim at sociobiology’s attempts to reduce human behavior to evolutionary formulas. “My mathematical training really helped,” Kitcher notes. “I found fault with the models. They took far too much for granted.” More deeply, he objected to extrapolating from insect colonies to human societies. “The environments are much more complicated in the human case,” he says. “There’s genuine gene–culture coevolution, and ignoring that leads to error.” That argument, alongside books by Lewontin, Rose, and Kamin, helped redirect evolutionary thought away from genetic determinism.

Kitcher’s later engagement with the Human Genome Project shifted his focus toward the ethics and governance of science. “It was that experience—going to Washington, talking to congressional staffers—that made me realize there’s a channel of transmission from research to policy to the public,” he says. “Philosophers had completely neglected how science relates to the public good.” From that realization came Science, Truth, and Democracy and a series of works arguing that scientific priorities should be democratically guided. “It’s very easy for fields of science to drift away from the concerns of a larger group of people,” he says. “We need mechanisms to focus research on questions people would agree are significant if they truly understood one another’s needs.”

That conviction led Kitcher deep into ethics and political philosophy, and eventually to John Dewey. “When I came to Columbia, Sidney Morgenbesser said to me, ‘You sound just like Dewey—have you read him?’ I said, ‘No, he’s impossible to understand!’” He laughs. “But Sidney told me to read The Quest for Certainty, and I was amazed. Dewey had been working toward all kinds of things I had struggled to articulate. My reading of him has always been a conversation between Dewey and me.”

Kitcher’s mature philosophy—what he calls pragmatic realism—weaves these threads together. “When we find something that works, we try to generalize it, to see where it works and where it breaks down,” he explains. “That’s how knowledge grows. It’s pragmatic, but it’s also realist, because success depends on how reality pushes back against us.” The result is a view of objectivity as what happens when “the key fits the lock”—when an approach reliably opens doors across different contexts.

His most recent book, The Rich and the Poor, turns these ideas toward inequality and climate change. “Ethical life has been around for 50,000 to 100,000 years,” he says. “It co-evolved with language as humans learned to cooperate.” For Kitcher, moral progress arises when people learn to “get inside another person’s head—to see the world from their perspective.” That empathy, he argues, is the engine of moral advance: “It’s what ended slavery, expanded opportunities for women, and changed attitudes toward sexuality.”

But he worries that the modern world is turning its back on that ethical capacity. “When you remove thinking about what’s good for everybody in the name of economic efficiency, you’re turning your back on what has made human progress possible,” he warns. The results, he says, are visible everywhere—from widening inequality to inaction on climate change. “Without a more egalitarian society, we won’t get the cooperation we need, and the future will be very hard indeed.”

Asked how he defines success, Kitcher’s answer is simple: “If I’ve given people an idea or approach that can make their lives go better, then that’s success for me.”

The 6Degrees team extends its heartfelt thanks to Phillip Kitcher for sharing his time, insight, and lifelong dedication to uniting science, ethics, and democracy. His work reminds us that progress—scientific or moral—depends on our ability to learn from one another, to see across divides, and to imagine a shared future worth striving for.