Philip Johnson-Laird is professor emeritus at Princeton University. He is one of the most influential cognitive scientists of all time, best known for developing the idea of “mental models.” Though if you really want to get a sense of how eminent he is, you have to look no further than his email address. You can find him at Phil at Princeton. That’s right. He is the Phil at Princeton University. It was a huge honor to talk to him for this conversation, as he’s long been one of my favorite cognitive scientists. My favorite paper of his is a lesser known article from 2002 called How Jazz Musicians Improvise. It’s part of a long-standing interest of his in understanding how our minds create complex, meaningful sequences—in this case, strings of notes—on the go. Phil didn’t start off planning to become an academic (he left school at age 15), and before he got on the academic track he worked as a jazz pianist. In this conversation we go deep into Phil’s background as a musician, and how that influenced his ideas about the mind. We also talk about his background working miscellaneous jobs for 10 years before starting university, marching in protests led by Bertrand Russell, the mentorship of Peter Wason, Phil’s first encounters with cognitive science, his relationship with the great George A. Miller, the genesis of the idea of mental models, how Phil’s understand of mental models has changed over the past forty years, and what the question of how jazz musicians improvise can tell us about how the mind works.