It has now been over fifty years since the publication of Thomas Kuhn’s The Structure of Scientific Revolutions (1962), a book considered by many to be one of the seminal works of the twentieth century. I do not regard it as such. Although it has spawned thousands of worshipful articles and books, it remains for me, at best, like Pet Rocks—a fad.1 When I first wrote this, I received instant criticism from my editor and others: fads are short-lived, while enthusiasm for Kuhn’s book has persisted for half a century. And unlike Pet Rocks, The Structure of Scientific Revolutions was never sold as a forting companion, a solution to urban loneliness in a post-industrial society. So not exactly Pet Rocks. Maybe what emerged was more of a cult. With Kuhn as leader, dispensing his own brand of pernicious intellectual Kool-Aid. (In John Milius’s 1982 movie Conan the Barbarian, a peddler tells Conan about the cult of Set: “Two, three years ago, it was just another snake cult. Now you see it everywhere.”)

A cult, then: misplaced admiration for a particular person or thing. Or maybe it is the Emperor’s New Clothes, a case of community madness, an almost inexplicable desire to believe in something nonsensical because others are doing so. The Structure of Scientific Revolutions itself feasts on the offal of innuendo and vagueness. It is, at best, an inchoate, unholy mixture of the work of others—Ludwig Wittgenstein, Charles Darwin, Rudolf Carnap, Norwood Russell Hanson, Alexandre Koyré, Jerome Bruner, and more. At worst, it is an assault on truth and progress.

Truth. Is there such a thing? Can we speak of things as unambiguously true or false?

Some philosophers and historians of science who are familiar with the controversies that have swirled around Kuhn’s work believe that most of the issues have been put to rest. I would argue otherwise. But just what are these controversies and why should anyone care? Why should you, the reader, care? I suppose it depends on whom you ask, but for me, they point to big questions—about how language attaches to the world, the nature of truth, reference, realism, relativism, progress. Questions that continue to demand answers. Can we have knowledge of the past? 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? Unfettered emission of greenhouse gases promotes global warming. Species evolve through natural selection. Can we meaningfully assess the truth of these assertions? In my book, The Ashtray, I discuss many aspects of Kuhn’s work—indeterminacy of reference, incommensurability, scientific change triggered by anomalies, Darwinian evolution as a model for the development of science, the relativism of truth, the social construction of reality, his philosophical idealism, and more. In each of these aspects, I have found it to be wanting and, more often than not, false, contradictory, or even devoid of content.

And then there is the specter of skepticism. Kuhn was a
 great skeptic, but like Des Esseintes, the antihero of Joris-Karl Huysmans’s 1884 novel Against Nature (“Lord, take pity on the Christian who doubts, on the skeptic who would fain believe”2), he both believed in something and, at the same time, hoped to undermine it. His skepticism fed on childhood doubts. Have we not all wondered whether the world really exists? Whether we are just figments of someone’s imagination or artifacts of some infernal computer program, like in a Philip K. Dick novel or The Matrix (1999)?
 It could be. Why not? But on the other hand, don’t we all have a strong predilection for realism? We perambulate in the real world. Let’s consult an authoritative source. The Stanford Encyclopedia of Philosophy defines realism as the belief that there are things that exist “independent of anyone’s beliefs, linguistic practices, conceptual schemes, and so on.”3 Chairs, tables, rugs. The furniture of the world.4 On a Victorian table, a well-thumbed copy of William Makepeace Thackeray’s Vanity Fair (1847), a red checked tablecloth, a vase of irises. The furniture of the world may be furniture—or the printed letters that form the first (prolonged) sentence of Thackeray’s novel:

While the present century was in its teens, and on one sunshiny morning in June, there drove up to the great iron gate of Miss Pinkerton’s academy for young ladies, on Chiswick Mall, a large family coach, with two fat horses in blazing harness, driven by a fat coachman in a three-cornered hat and wig, at the rate of four miles an hour.

In fiction, we are often given an imaginary world with seemingly real objects—horses, a coach, a three-cornered hat and wig. But what about the objects of science—positrons, neutrinos, quarks, gravity waves, Higgs bosons? How do we reckon with their reality?

And truth. Is there such a thing? Can we speak of things as unambiguously true or false? In history, for example, are there things that actually happened? Louis XVI guillotined on January 21, 1793, at what has become known as the Place de la Concorde. True or false? Details may be disputed—a more recent example: how large, comparatively, was Donald Trump’s victory in the electoral college in 2016, or the crowd at his inauguration the following January?5 
But do we really doubt that Louis’s bloody head was held up before the assembled crowd? Or doubt the existence of the curved path of a positron in a bubble chamber?6 Even though we might not know the answers to some questions—“Was Louis XVI decapitated?” or “Are there positrons?”—we accept that there are answers.

Does language connect us to the world or lead us back to ourselves? Or are we hopelessly trapped inside our skulls?

And yet, we read about endless varieties of truth. Coherence theories of truth. Pragmatic, relative truths. Truths for me, truths for you. Dog truths, cat truths. Whatever. I find these discussions extremely distasteful and unsatisfying. To say that a philosophical system is “coherent” tells me nothing about whether it is true. Truth is not hermetic. I cannot hide out in a system and assert its truth. For me, truth is about the relation between language and the world. A correspondence idea of truth. Coherence theories of truth are of little or no interest to me. Here is the reason: they are about coherence, not truth. We are talking about whether a sentence or a paragraph
 or group of paragraphs is true when set up against the world. Thackeray, introducing the fictional world of Vanity Fair, evokes the objects of a world he is familiar with—“a large family coach, with two fat horses in blazing harnesses, driven by a fat coachman in a three-cornered hat and wig, at the rate of four miles an hour.” Were Thackeray describing a real scene, his sentence would be true if (and only if) the horses and coachman were fat, the hat three-cornered and sitting atop a wig, and the coach indeed moving at a rate of four miles per hour.

We are approaching a nasty problem: the relation between meaning, truth, and reality. Words and worlds. How do the words we use relate to things in the world? What links the beliefs and associations I attach to words—buzzings in the ball of electric jelly inside my skull—to objects in the world around me? Strictly speaking, it is not mind-body; it is language-world.

Does language connect us to the world or lead us back to ourselves? Is there a relation between things in our head (e.g., the beliefs we have about things) and things in the world (e.g., the furniture of the world)? Or are we hopelessly trapped inside our skulls?

On September 4, 2011, I interviewed philosopher Hilary Putnam, a some-time critic of Kuhn, in his home in Boston. I asked him—paradigm shifts, incommensurability, reference and belief—could it all come down to tissues of translation? Can we translate one language into another? One theory into another?

Putnam, who died in 2016, was a fixture around Cambridge, a former professor at Princeton and MIT, then at Harvard since the 1960s. On Rosh Hashanah and Yom Kippur, Jewish High Holy Days, services are held on the Harvard campus at Sanders Theater, a spectacular Gothic Revival pile with an elaborately carved wood interior. Putnam, along with the cantor, the rabbi, and other officials, would preside over the services. I cannot entirely explain it, but I took enormous comfort in seeing him there. I thought he could help me get written into the Book of Life.

Few philosophers have wrestled with such a range of questions over such an extended period of time. I had lived in Cambridge and attended Putnam’s lectures in 1970–71, the year before I went to Princeton.

HILARY PUTNAM: So how did you come to take my course? You weren’t a Harvard graduate student.

ERROL MORRIS: No. I was applying to the History of Science Department. And you were teaching a course on Kurt Gödel’s proofs.

HP: Well, I never—I taught an upper-level math department course on Gödel and Paul Cohen’s proofs.

EM: You were supposed to be teaching a course on Gödel, but you were using Mao’s Little Red Book.

HP: [Laughs.] So it had to be the sixties, because I quit Progressive Labor in 1972.7

EM: This was 1971. You never got around to Gödel. But you discussed Richard Herrnstein and IQ tests. [Herrnstein wrote a controversial book on the inheritability of IQ.] You gave an example—I believe it was a multiple-choice question—about the word “angler.” Do you remember this?

HP: No. All these stories about my past—they come back as stories about an interesting fellow I would have liked to know, or the opposite.

If Kuhn’s incommensurability theory were true then we could not translate other languages—or even past stages of our own language—at all.

EM: “Angler.” One of the answers was “(A) fisherman.” And then, “(B) mountain climber.” And kids from Harlem would answer, (B) mountain climber.

HP: You are going up at an angle. Things that we would not even recognize as culturally biased. Maybe because people do not want to know.

EM: Yes, there is a strong desire not to know things.

HP: There is a term from St. Aquinas. I have to look it up. It is for “not knowing something because you do not want to know it.”

We were sitting in Putnam’s book-lined living room. His wife of more than fifty years, Ruth Anna Putnam, a Wellesley College professor emerita, was writing in the kitchen. A female voice called out, “Willful ignorance.” No doubt they had spent countless hours working separately but together. One room apart. I thought this must be what true love is all about.

HP: Willful ignorance? I am not sure. I think it is in Latin. I will have to look it up.8

EM: One of the reasons I wanted to talk with you—part of it is revisiting that period: the late 1960s, early ’70s. Part of it is reckoning with my experiences as a graduate student with Tom Kuhn. There is a passage in Reason, Truth and History where you call Kuhn’s use of incommensurability incoherent.

Putnam captures many of my complaints about Kuhn. (I wish he had been in the room to defend me when Kuhn threw an ashtray at me in rage.) He writes:

The incommensurability thesis is the thesis that terms used in another culture, say, the term ‘temperature’ as used by 
a 17th century scientist, cannot be equated in meaning or reference with any terms or expressions we possess. . . . If this [incommensurability] thesis were really true then we could not translate other languages—or even past stages of our own language—at all. . . . To tell us that Galileo had ‘incommensurable’ notions and then to go on and describe them at length is totally incoherent.9

HP: Yes. I still stand on that criticism of Kuhn. He was too much of an antirealist for me, even at my most antirealist.

EM: Too antirealist for you?

I read the passage back to Putnam.

HP: Yes. He had various escapes. In the course of our long debates—I knew him well, over the years—my original take was, “Look, we can talk about grass. For the average educated person it is virtually a necessary truth that plants live by photosynthesis.”

EM: The Tea Party might not accept that.

HP: [Laughter.] The notion of “grass” is now interconnected with notions like “chlorophyll,” “photosynthesis,” and so
on. So if this is all incommensurable, then “grass” cannot be translated—textbooks cannot be translated, the word “grass” in
 an eighteenth-century English novel cannot be translated into twentieth-century English. John Austin, whose gift with words I very much admired, once said of philosophers, “There’s the bit where you say it and the bit where you take it back.”10 So there is a place where Kuhn says different theories live within different words, then takes it back. From an analytic philosopher’s point of view, he loads the cards. According to Kuhn, to say what an ancient text means, you have to have synonyms in the present scientific language for the old concepts—which is not true. Absolutely not true. My father was a translator—the Samuel Putnam Don Quixote is my father’s translation. The Modern Library version. And every translator knows that you have to explain what people are talking about even though you do not have an exact synonym. Excellent examples of this occur in Benjamin Lee Whorf.

‘We should always be able to find some level of agreement from which a discussion can begin. And then we will either find insistence on doctrine independent of fact, which you cannot debate, or else we will find a rational resolution.’

Benjamin Lee Whorf (1897–1941), an American linguist, spent much of his life working for the Hartford Insurance Company, like the poet Wallace Stevens. Whorf’s essays on language, published more than a decade after his death, were incorporated into a volume entitled Language, Thought, and Reality. Whorf’s central idea—sometimes called “linguistic relativity” or the Sapir-Whorf hypothesis, named for him and his teacher Edward Sapir—argues that how we see the world is determined by the language we use. That different cultures—for example, Shawnee and Hopi, which Whorf studied— have different languages means that their members see the world differently. Indeed, Whorf argues that the Hopis have a different conception of time because of the construction of their language. The Hopis, the Shawnees, and we exist (to use Kuhnian language) in different linguistic worlds:

We dissect nature along lines laid down by our native languages. The categories and types that we isolate from the world of phenomena we do not find there because they stare every observer in the face; on the contrary, the world is presented in a kaleidoscopic flux of impressions which has to be organized by our minds—and this means largely by the linguistic systems in our minds.11

It is Whorf’s argument that our linguistic systems constrain what we can and cannot think.12 Reality must be derived from our linguistic systems, not the other way around. Could Whorf be a precursor of Kuhn? Whorf writes:

We are thus introduced to a new principle of relativity, which holds that all observers are not led by the same physical evidence to the same picture of the universe, unless their linguistic backgrounds are similar, or can in some way be calibrated.13

What did Putnam think?

HP: Kuhn is saying that since you cannot translate, synonym by synonym, Newtonian physics into relativistic physics, it follows that—according to Kuhn, anyway—they are incommensurable. Kuhn, in replying to your objection would have taken the other side and said, “Yes, but I am not saying that I cannot say what the world of Newtonian physics was like. Incommensurable does not mean we cannot describe it. It just means we cannot translate it.”

EM: You can describe it, but you cannot translate it?!

HP: Yes. For Kuhn, it ultimately depends on his antirealism, his rejection of all talk of real objects. Because if you think that there are real things out there to which our present terms refer, then you can say what they were referring to when they talked of distance in Newtonian times.

EM: There is a kind of comfort—that when you are talking about something, you are really talking about some thing. Even though our beliefs change—our references do not! As you say, languages are translated, retranslated, and words are added and subtracted. Our beliefs are in flux, but that does not mean that reference is in flux.

HP: Yes.

I felt Noam Chomsky would be an ideal person to consult about scientific change, and Kuhn, as well as reference and truth. (Both had taught at MIT after Kuhn left Princeton.) Chomsky’s ideas are often—at least for me—difficult to understand. And I hoped by talking with him, I could come to a deeper understanding of some of his philosophical positions and his thoughts about Kuhn and history of science. For example, on scientific revolutions. For Chomsky, it is “revolution” in the singular. There is only one. The Scientific Revolution—the revolution from pre-Galilean narratives to a post-Galilean mathematical world picture. Chomsky has gone on record saying that even his own “revolution” in linguistics (his rejection of Skinner and the behaviorist school) was no revolution at all.14 He wrote to me, “There’s no criterion to determine whether some change is a scientific revolution. It’s a matter of judgment.”15 (Hear, hear. I myself would argue that many scientific revolutions never occurred but were imagined long after the fact, just as the neo-Platonists in the fourth and fifth centuries CE imagined the murder of Hippasus over his supposed proof of the irrationality of √2.)

So no scientific revolutions. What about realism?

I would call Chomsky a reluctant realist, a realist about scientific terms but not about terms in ordinary language. “In the sciences, one goal is to adhere as closely as possible to the referentialist doctrine. Thus in devising technical notions like electron or phoneme, researchers hope to be identifying entities that exist in the world, and seek to adhere to the referentialist doctrine in using these notions.”16

The phrase “referentialist doctrine” is a fancy way of describing the idea that there are things (entities) in the world to which we can unambiguously refer. In ordinary language, Chomsky argues, the doctrine fails. If reference is a mind-world relation—a relation between some specific thing in the mind (or brain) and some specific thing in the world—our attempts fall short. We are archers hoping to hit targets when, properly speaking, we cannot even say the targets exist, let alone whether we hit them.

In the elementary case, a name like Pavarotti “refers to or denotes its bearer (the popular singer)”; and generally, “from
 a denotational point of view, symbols stand for objects.” This core notion—the referentialist doctrine—is standard, as indicated even in the titles of some of the founding works on these topics in the early days of contemporary linguistic semantics over half a century ago: Words and Things (Brown 1958) and Word and Object (Quine 1960). And of course the referentialist doctrine has much deeper roots. . . . [Some] argue that it should serve a dual function, leading to explanation of the two fundamental questions of semantics: the link between symbols and their information content, the “aboutness of language,” its connection to the external world; and “language as a social activity.”17

Chomsky believes we are making some kind of leap when we imagine that we have referred to anything outside of our conceptual schemes. But still, for Chomsky there is no incommensurability. (That is, there can be an absence of metaphysical certainty without the gobbledegook of Kuhnian paradigms.) There is our common human conceptual scheme and no other. He dismisses the issue
 with a rhetorical question: “Can you think of cases where apparent incommensurability has remained as a barrier to scientific progress?”

NOAM CHOMSKY: As far as I can see, there is too much commonality of cognitive capacities for there to be anything like incommensurability. We should always be able to find some level of agreement from which a discussion can begin. And then we will either find insistence on doctrine independent of fact, at which point, of course, you cannot debate anymore, or else we will find a rational resolution. So, for example, if you are debating evolution with an evangelical Christian who is committed to a belief in the literal truth of the Bible, you reach a point where you cannot carry out a discussion anymore. But there is nothing profound about that. That is just insistence on doctrine independent of evidence.

EM: Dogmatism.

NC: Yes. But if you do not have that kind of irrational factor, it is hard for me to believe that there is no way to move from some shared set of assumptions to a serious interaction—it is not that you cannot understand one another.

EM: Even in the case of the Bible-thumping evangelist and, say, Richard Dawkins, there still is a discussion.

NC: Exactly. They understand one another, and they have their beliefs that are unshakable no matter what the facts are.

EM: Indeed, it happens all the time.

NC: Yes, of course.

Reprinted with permission from The Ashtray: Or, the Man Who Denied Reality. © 2018 by Errol Morris. Published by the University of Chicago Press. All rights reserved. 


1. Developed in 1975 by Gary Dahl, an advertising executive, Pet Rocks sold for four dollars a piece. Dahl quickly sold over a million and a half of them. The Structure of Scientific Revolutions, which celebrated its fiftieth anniversary in 2012, has sold roughly the same number of copies. [Return]

2. Huysmans, À Rebours (1972), p. 206. [Return]

3. Alexander Miller, “Realism.” [Return]

4. “Furniture of the world” is a phrase used in ontology, the branch of philosophy concerned with the question of what things exist. What is real. I tried to track down the origins of the phrase, with limited success. I vaguely remembered reading it in Bertrand Russell. And my researcher Josh Kearney did find a reference in Russell’s Introduction to Mathematical Philosophy (1920), p. 182. Addressing the question of whether classes of things exist, Russell remarks, “The first thing is to realize why classes cannot be regarded as part of the ultimate furniture of the world.” Kearney also located Barry Sandywell’s entry “Furniture of the World,” in Dictionary of Visual Discourse (2016): “The phrase ‘store and furniture’ applied to the world can be found in John Ray’s The Wisdom of God Manifested in the Works of Creation (1717 . . .). The closest relative of this expression applied to philosophical topics makes a classical appearance in George Berkeley’s The Principles of Human Knowledge (§6). . . . It is notable that the expression ‘furniture of the world’ is a hybrid phrase of Berkeley’s furniture of the earth’ and ‘the mighty frame of the world.’ ” [Return]

5. Members of the Trump administration have denied the relevance of truth and suggested that there are such things as “alternative facts”—in short, that history is up for grabs and can be defined by those in power. This book, I hope, will serve as an antidote to those poisonous views. Truth and the apperception of truth, in my view, are what make civilization and progress possible. The denial of these things ultimately, perhaps irrevocably, undermines civilization. Many may see this book as a vendetta. Indeed, it is. I find Kuhn’s advocacy of the social construction of knowledge to be deeply disturbing, even pernicious. He was certainly not the only person to propound such ideas. But I am still possessed by the image of Kuhn cloistered in his office at the Institute for Advanced Study, writing about the absence of progress in science while bombs were dropping over Southeast Asia. The reader may think the two have nothing to do with each other. For me, they are inseparably connected. [Return]

6. “An invisible high-energy electrically-neutral light particle (photon) travels down from the top of the image and scatters off an invisible neutral hydrogen atom that is located near the middle of the figure, where the three curves meet at a cusp. The collision of the photon with the atom causes four particles to appear: a positively charged proton (not visible), a negatively charged electron knocked free from the hydrogen atom (this corresponds to the nearly straight track continuing downwards), and the creation of two new particles, a negatively charged electron and a positively charged antiparticle called a positron, whose paths trace out the two spirals.” (Henry Greenside, “Creation and Conservation of Charge during Electron-Positron Particle Production from a Photon” [2015].) Such images illustrate one of the most important results of modern physics, the direct conversion of energy into matter. [Return]

7. Progressive Labor was considered a Maoist party. But in 1972, it ended its support of the Cultural Revolution and split with the People’s Republic of China. [Return]

8. The reference is to Thomas Aquinas, Summa Theologica, part I–II, question 76, articles 1–3. [Return]

9. Putnam, Reason, Truth and History, pp. 114–15. Essentially he is telling us that we should always be suspicious of those who counsel abstinence and then try to seduce their listeners. [Return]

10. J. L. Austin, Sense and Sensibilia (1964), p. 3. [Return]

11. Whorf, Language, Thought, and Reality (1956), p. 213 (emphasis mine). [Return]

12. Steven Pinker eviscerates Sapir-Whorf in The Language Instinct (2000), pp. 48–57. Philosopher Donald Davidson has also ridiculed Whorf’s ideas of linguistic relativism, relating them to Kuhn: “Whorf, wanting to demonstrate that Hopi incorporates a metaphysics so alien to ours that Hopi and English cannot, as he puts it, ‘be calibrated’, uses English to convey the contents of sample Hopi sentences. Kuhn is brilliant at saying what things were like before the revolution using—what else?—our post-revolutionary idiom.” Inquiries into Truth and Interpretation (1984), p. 184. [Return]

13. Whorf, Language, Thought, and Reality, p. 214. [Return]

14. Chomsky, Gary A. Olson, and Lester Faigley, “Language, Politics, and Composition” (1991), p. 2. [Return]

15. Email to author, August 4, 2014. [Return]

16. “Notes on Denotation,” p. 42. The italics on “hope” are mine. It is a peculiar word here. Hence, it is given a quasi-religious significance. (Like transubstantiation.) [Return]

17. “Notes on Denotation,” p. 38. [Return]