William McGowen “Mac” Priestley died peacefully at his home on June 22, 2022, at age 81. Mac was raised in Rosedale, Mississippi. He graduated from The University of the South in 1962 and went on to earn a PhD at Princeton. He returned to Sewanee in 1967 to teach mathematics for 44 years. An avid reader, writer, and conversationalist who found wisdom and beauty in words and numbers, Mac believed in the intrinsic good of an educated and curious life.