REUBEN HERSH, (1927-2020), was professor emeritus at the University of New Mexico, Albuquerque. He was the recipient (with Martin Davis) of the Chauvenet Prize and (with Edgar Lorch) the Ford Prize. Hersh was the co-author (with Philip J. Davis) of The Mathematical Experience and Descartes' Dream, which won the National Book Award in 1983, and author of What is Mathematics, Really?
He advocated for what he called a "humanist" philosophy of mathematics, to both Platonism (so-called "realism") and its rivals nominalism/fictionalism/formalism. He held that mathematics is real, and its reality is social-cultural-historical, located in the shared thoughts of those who learn it, teach it, and create it. His article "The Kingdom of Math is Within You" (a chapter in his Experiencing Mathematics, 2014) explains how mathematicians' proofs compel agreement, even when they are inadequate as formal logic.
