Oscar-winning filmmaker Errol Morris's recent book is Believing Is Seeing: Observations on the Mysteries of Photography. Ron Rosenbaum (smithsonian.com) reviews it here.
Rosenbaum tells the story of how Morris enrolled in a graduate philosophy seminar at Princeton, taught by Thomas Kuhn. Kuhn is the one who coined the term "paradigm shift." Way back in the 1970s I had to read Kuhn's ultra-famous The Structure of Scientific Revolutions. It stayed with me, so much so that I ended up making Kuhnian paradigm-connections to a theory of metaphor (how metaphor works) in my doctoral dissertation.
In class, Morris conflicted with Kuhn. At the end of one argument Kuhn threw an ashtray at Morris, almost cracking his skull. (Kuhn was an incredible chain smoker.) Morris writes about this incident here. It's fascinating reading, and funny.
Morris had a Harvard professor, Erwin Hiebert, write a letter of recommendation to Kuhn at Princeton. Morris got accepted by Princeton. Morris writes: "I should have known that there was going to be trouble. I had imagined graduate school as a shining city on a hill, but it turned out to be more like an extended visit with a bear in a cave." That bear was Kuhn. The matter of conflict was the nature of truth.
Paradigms, for Kuhn, were "incommensurable." (I now remember attending, as an undergraduate, Harold I. Brown's course on Kuhn, and trying to grasp Kuhnian thinking, which was new to me.) Kuhn's incommensurability thesis is this: if theories are incommensurable, there is no way in which one can compare them to each other in order to determine which is more accurate. See a footnote Morris makes on this below.
As Kuhn was presenting this in class, Morris the student asked: “If paradigms are really incommensurable, how is history of science possible? Wouldn’t we be merely interpreting the past in the light of the present? Wouldn’t the past be inaccessible to us? Wouldn’t it be ‘incommensurable?’
A great question! But, upon hearing this, Kuhn put his head in his hands and began muttering, "He's trying to kill me. He's trying to kill me."
"And then I added, “…except for someone who imagines himself to be God.” It was at this point that Kuhn threw the ashtray at me. And missed.
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."
Kuhn's view was that truth is culturally determined and depends on a person's "frame of reference." With this, welcome to one of the roots of postmodernism. (See footnote 18 below, from Morris's nytimes essay.)
Harris's position was then, and remains, that reality and truth are not, ultimately, about one's perspective. For example, I tell my logic students that the state The lights in this room are on is either true or false. If it is true, it is true for everyone past, present, and future. If it is false it is false for everyone. "Truth," in logic, is not subjective or perspectival. If someone says From my limited perspective the lights in this room are on, then that statement, if true, is true for everyone. My logic text (Vaughn) is exceptionally good on clarifying this and defeating the "subjectivist fallacy" as self-contradictory.
"Truth may be elusive, it may even be unknowable, but that doesn’t mean, as postmodernists aver, that reality is just a matter of subjective perspectives, that one way of seeing things is just as good as another.
“I’m amazed,” Morris said when we spoke recently, “that you still see this nonsense all over the place, that truth is relative, that truth is subjective. People still cling to it.” He calls these ideas “repulsive, repugnant. And what’s the other word? False.”"
I am certain that "reality is [not] just a matter of subjective perspectives." That's the "logic" in me. I am also persuaded that all facts are theory-laden; i.e., we all view reality through an epistemic filter. I think all of us, now, see epistemically "through a glass, darkly." I think, to get at this, we do well to first adjudicate between noetic frameworks (worldviews; noetic frameworks). By such frameworks we see clearly.
 “Incommensurability” is a term introduced by Kuhn in “The Structure of Scientific Revolutions.” Although it is used repeatedly in the book, Kuhn offers no clear definition. Much of this essay is an attempt, albeit an unsuccessful one, to pin it down. Here is a sample of some of Kuhn’s explanations: (1) “The normal scientific tradition that emerges from a scientific revolution is not only incompatible but often actually incommensurable with that which has gone before.” (2) “These examples point to the…most fundamental aspect of the incommensurability of competing paradigms. In a sense that I am unable to explicate further, the proponents of competing paradigms practice their trades in different worlds.” And (3) “Just because it is a transition between incommensurables, the transition between competing paradigms cannot be made a step at a time, forced by logic and neutral experience. Like the gestalt switch, it must occur all at once (thought not necessarily in an instant) or not at all.” Thomas Kuhn, “The Structure of Scientific Revolutions.” Chicago: University of Chicago Press. 1996. pgs. 103, 150
 I can’t hope to provide a definition of postmodernism here. But the essence of it, for me, is the social construction of reality and of truth. Forgive me, this definition may not capture the many varieties of postmodernism, but it’s the best I can do. I had never really thought of Kuhn as a postmodernist, but one of my researchers returned with a syllabus from Louis Menand’s Harvard class on postmodernism and on the list of required reading, along with Lyotard, Baudrillard and Derrida, was “The Structure of Scientific Revolutions.” Structure became an “important text” of postmodernist thought.