Skip to main content


A filmmaker with an ax to grind takes aim at Thomas Kuhn’s legacy

The Ashtray (Or the Man Who Denied Reality)

Errol Morris
University of Chicago Press
223 pp.
Purchase this item now

Thomas Kuhn, an American physicist, historian, and philosopher of science, achieved prominence with the 1962 publication of his influential book, The Structure of Scientific Revolutions. Science, it contended, does not generate incrementally truer descriptions of reality but develops through radical paradigm shifts. Kuhn’s theory of scientific revolutions motivated expansions and reactions that reconfigured the history and philosophy of science.

Errol Morris, an acclaimed documentary filmmaker who briefly studied under Kuhn at Princeton, instead remembers the acerbic philosopher for flinging the titular ashtray at him during an argument in 1972. Morris hurls The Ashtray back, targeting not Kuhn’s person but his legacy. “Our posttruth moment is all Thomas Kuhn’s fault” would be an unfair summation of the book—but only just.

Structure, Morris writes, brutalized the truth, and Kuhn was an avatar of postmodernism who rejected the external world’s very existence. Deep personal animosity—so overt that he compares Kuhn to Hitler in his acknowledgments—fuels Morris’s critiques.

A filmmaker’s sensibility informs the book’s cadence; rather than demonstrating Kuhn’s errors, Morris conjures an image of his wrongness. He interweaves philosophical explication, cultural allusion that careens between the highbrow and the low, interviews with authoritative figures, and copious illustrations. Incommensurability is his principal target.

Kuhn’s notion that adherents of one paradigm inhabit a different mental world from, and cannot communicate meaningfully with, those of another is the most radical element of his philosophy. Morris, who favors Saul Kripke’s causal theory of reference, considers incommensurability to be epistemic anarchy.

For Kripke, theoretical commitments do not bedevil our linguistic reference to things. Morris adjudges Kripke’s philosophy a firm foundation for scientific knowledge, setting up a choice: “Does science progress toward a more truthful apperception of the physical world? Or is it all a matter of opinion, a sociological phenomenon that reflects consensus, not truth?” Hard-nosed scientific certitude or frothy-lipped relativism?

This dyad, too neat to encapsulate Kuhn’s legacy, recalls Morris Zapp, the bumptious protagonist of David Lodge’s Changing Places. Zapp had a mission: a series of Jane Austen commentaries so panoptic “that when each commentary was written there would be simply nothing further to say about the novel in question.”

The joke, of course, is the perfect totality with which any such endeavor escapes the point. We don’t study literature in search of finality but to enable new ways of thinking. Daniel Dennett makes a similar suggestion about philosophy, asking whether it would be preferable to be so definitively correct that you foreclose an area of inquiry or to err so spectacularly that people debate your blunders for centuries. Scientists tend to choose the former, philosophers the latter.

Kuhn had many fecund failures. Structure, for all its flaws—many of Morris’s specific critiques are apt—forced new approaches to questions about how scientific truth claims arise in practice. Morris might even have been inclined to agree, if not for the depth of his animus. “The role of a good documentary,” he once told the Boston Globe, “is not to convince you about what happened, but to force you to think about what happened.”

Theories of reason and reference describe the clean, ideal ways that our minds might latch onto the world. But the practice of science is far messier. Kuhn sensitized historians and philosophers to that messiness. He wondered how philosophy would have to adapt if it countenanced the historical processes by which scientists actually achieved understanding. Close scrutiny reveals those to be profoundly dissimilar to the tidy philosophical frameworks Morris favors, which are little informed by, and have scarcely influenced, the practices that provide the sturdiest accounts of the natural world.

Morris charges Kuhn with undermining the truth and authority of science. But that authority, the crux of cultural battles over climate change and evolution, has less to do with abstract, transcendent truth than with reliability, consensus, and the social processes that enable them.

The ironclad truth Morris seeks, so integral to the popular image of science, is one of science’s greatest vulnerabilities. A responsible scientist will always admit doubt. Combined with the widespread perception that science seeks irreproachable truth, that is a powerful weapon for those who would undermine scientific authority.

Thomas Kuhn was unkind to Errol Morris. By all accounts, he was often unkind. That kindness and influence so frequently fail to intersect is a bitter injustice. But so, too, is vilification in the service of vendetta.

About the author

The reviewer is at the Department of History and Philosophy of Science, University of Cambridge, Cambridge CB2 1TN, UK.