The filmmaker Errol Morris began his career as a graduate student in the philosophy of science, and has just published the beginnings of his account of his encounter with Thomas Kuhn, then a visiting scholar at the Institute for Advanced Study, which ended with Kuhn's hurling an ashtray:

I see the arc, the trajectory. As if the ashtray were its own separate solar system. With orbiting planets (butts), asteroids and interstellar gas (ash). I thought, "Wait a second. Einstein's office is just around the corner. This is the Institute for Advanced Study!!"

I call Kuhn's reply "The Ashtray Argument." If someone says something you don't like, you throw something at him. Preferably something large, heavy, and with sharp edges. Perhaps we were engaged in a debate on the nature of language, meaning and truth. But maybe we just wanted to kill each other.

The end result was that Kuhn threw me out of Princeton. He had the power to do it, and he did it. God only knows what I might have said in my second or third year. At the time, I felt that he had destroyed my life. Now, I feel that he saved me from a career that I was probably not suited for.

I heard Morris lecture on the subject at Princeton and am looking forward to the rest of his series. I also knew Thomas Kuhn in the late 1970s, when I was starting out as science editor at Princeton University Press.

My own relationship to Thomas Kuhn was very different. Kuhn, I now realize in hindsight, was the person who did most to stimulate my early interest in unintended consequences. He was one of the most fortunate people I knew, it seemed -- with a best-selling academic book, chairmanship of a prestigious program with an even more exalted endowed chair, and (it was said) independent wealth. His idea of the "paradigm shift," the discontinuous change of outlook, had become what the evolutionary biologist Richard Dawkins had just labeled a meme, a self-replicating idea spreading across the culture.

Kuhn did not seem especially happy about all of this. Popular applications of his ideas generally alarmed him. Kuhn lived to see Structure of Scientific Revolutions cited in 1993 as Vice President Al Gore's favorite book, yet he was dismayed about what would later be called going viral. Perhaps all of us really want the unattainable, but to Kuhn it wasn't enough to be the world's most discussed historian of science. Kuhn had been denied tenure twice -- first at Harvard, then at Berkeley, where philosophy, his preferred department, had recommended him for tenure only in history.

Some people would have treated an endowed Ivy League chair and a bestselling book as vindication enough. Kuhn didn't care what Wall Streeters or politicians thought of his ideas. He wanted recognition from philosophers and worked for the rest of his life revising the ideas in Structure to satisfy their many criticisms of inconsistent use of "paradigm shift." And as a careful student of scientific texts -- he was famous for advising students to focus not on what anticipated today's ideas but on what looks strangest now -- he was dismayed by the use of his ideas by social historians of science, and I wouldn't be surprised if other episodes of rage came to light.

Morris thus was lucky not only to dodge the ashtray -- assuming it was aimed to harm -- but to end his association with Kuhn and the academic life that was not for him. Imagine if Kuhn had been patient and understanding, a model graduate teacher. We might have lost a great filmmaker. Teachers and bosses often inadvertently guide people to their real callings. I've called this schmentoring. Sometimes we should be grateful for bad behavior.