Errol Morris had an intriguing series of essays published this week at the New York Times. They are entitled “Incommensurability,” and are an exploration into a philosophical idea about the social nature of science and knowledge. It turns out that Morris took a graduate seminar in philosophy from Thomas Kuhn, a writer from whom I’ve stolen some very good ideas. The climax of this relationship, from Morris’ perspective, was when Kuhn threw an ashtray at his head. The reason for this assault was Morris needling Kuhn about a problem regarding incommensurability.
Kuhn was a scientist and a historian of science more than a philosopher, but the ideas he had to formulate to make sense of his interpretations of science’s history were deeply philosophical. Key to Kuhn’s own understanding of the history of science, and the focus of Morris’ essay, was the concept of incommensurability. Science was not a progress toward better and better knowledge of the world, as traditional ways of writing its history would have it. The history of science actually consisted of a variety of models, ways of understanding the world and articulating problems that are largely unrelated to each other.
Revolutionary periods in science were the time when new models were created and become prominent enough to challenge the old models. This usually happened when some problem that the old model couldn’t make sense of become too noticeable to ignore. Those practicing one model understood the world in a totally different way than those practicing another model. The terms of one model only make sense within that model; to translate terms from one model to another would remove all the distinctive characteristics from the translated model. This is what it means to be incommensurable.
Morris explains that he confronted Kuhn with a problem of incommensurability: If two broadly defined ways of seeing the world were truly incommensurable, which Kuhn assured him they were, then a historian of science in the mid 20th century could never truly understand the scientific worldview of the medieval Europeans or ancient Greeks. The history of science itself should be impossible. And the ashtray flew.
Morris goes through several intriguing examples from history and philosophy and the history of philosophy to illustrate his points about the problem of the incommensurability concept. They are quite fascinating, but they all add up to the same point: If different models of understanding the world are genuinely incommensurable, then holders of different models shouldn’t be able to understand each other at all. Yet the conflicts among models of understanding the world seem to be motivated precisely because their opponents understand the new model. Read the articles and think about it.
Are you finished? Good.
I first heard of Errol Morris when I saw his documentary about the career of Robert McNamara, The Fog of War. I thought it was a brilliant exploration of how a sharp, intelligent, and empathetic person found himself becoming the architect of one of the most terrifying mistakes the American government ever made: its invasion of Vietnam. As I started hearing more about Morris’ history, I was less impressed.
When his filmmaking career began, Morris was friends with Werner Herzog, and would always talk to Herzog about this idea he had for a documentary about pet cemetaries and the people who use their services. But he would always come up with excuses as to why the film could never get off the ground. Finally Herzog said that if Morris ever actually got his film made, Herzog would eat the very boots that he was wearing at the time of the challenge. Morris made Gates of Heaven, and at its festival premiere, Herzog ate the boiled shoes from the challenge. The result was another short documentary: the hilarious Werner Herzog Eats His Shoe. But it took a shoe eating challenge from Germany’s greatest living director to get it off the ground. I discovered on the commentary for Herzog’s Stroszek that this film was generated when Herzog went to rural Wisconsin to help make a documentary about Morris’ early life. But Morris never showed up, so Herzog wandered around small-town Wisconsin himself, coming up with ideas for the film that eventually became Stroszek. A wonderful result, but borne of Morris’ scatterbrained laziness.
Perhaps despite of these habits of his personality, Morris has written a fine series of articles that work a general audience through complex philosophical problems. The project suffers, I think, from the prominence that having an ashtray whipped at his head plays in his memories of Kuhn. That confrontation colours his entire view of Kuhn: With every interaction they had about what incommensurability meant, Morris thought Kuhn's anger was a sign that Morris was getting to the older man, forcing him to deal with something he didn't want to admit. Having won the staring contest, Morris presumes his suspicions were right, and doesn't think about the miscommunication he and Kuhn could have had from the beginning. I don't blame him for being affected by nearly being knocked out with an ashtray, but there is more nuance to Kuhn's (or at least Kuhn-inspired) thinking than Morris suggests.
It doesn’t require a purely objective perspective, a god’s eye view, or a view from nowhere to understand a way of making sense of the world that is alien to your own. All you need are skills of observation and disciplined, careful imagination. I think Morris makes a mistake in calling incommensurability the absolute separateness of some way of understanding from another, that someone who thinks according to paradigm A couldn't possibly understand anything of paradigm B. If this were true, there was no way for anyone to do any history of science at all: every view that differed from our own would be dismissed as nonsense. But one can think about one's own premises of thinking, and do so for any paradigm of thinking you care to investigate. In understanding how a paradigm of thought arises and evolves, one understands that paradigm.
Incommensurability is a matter of practical work, not pure understanding. A phlogiston chemist can't test for oxygen, because the structure of phlogiston chemistry doesn't include oxygen, or much of the periodic table. That phlogiston chemist could learn the basic concepts of a periodic table chemist, just as the periodic table chemist could learn how phlogiston theories work. But you couldn't do chemistry experiments using both theories at the same time. They can be understood, from a perspective of self-reflexivity, reflexive criticism. But when it comes to the work, you have to choose one or the other.