Every death is the shutting of a book, but when William H. Pierson, the prominent historian of architecture, died last December, it seemed more like the close of a geological era. He was the last survivor of that trio of extraordinary—and extraordinarily long-lived—Williams College professors who for a half century were major forces in the world of American art. All lived to be nonagenarians and remained professionally active to the end, not only Pierson (1911–2008) but Lane Faison (1907–2006) and Whitney Stoddard (1913–2003) as well. Through a travesty of language they were dubbed the “Holy Trinity,” to their great chagrin, while their former students became known as the “Williams Art Mafia.” The metaphors are grotesquely mixed: It hardly seems decent that a Puritan establishment like Williams should be trafficking in trinities and mafias. (To be sure, the more h ...