Frank Jackson

There is a rare kind of intellectual courage that consists not in defending a position but in abandoning one you made famous. In 1982 Frank Jackson published “Epiphenomenal Qualia” and inside it placed Mary’s Room: a scientist raised in a black-and-white room who knows every physical fact about color vision and yet, on seeing red for the first time, seems to learn something new. The argument was clean, devastating, and aimed at the heart of physicalism, the doctrine that the physical facts are all the facts. It became one of the most discussed arguments in the philosophy of mind. And then, over the following two decades, its own author decided it was wrong. He came to believe that Mary learns nothing over and above the physical, that the intuition the argument trades on is—in his own words—a triumph of philosophical ingenuity over common sense, and he reclassified himself as a physicalist. The man who built the most elegant case against physicalism