It is hard to think of two philosophers less alike than St. Thomas Aquinas and Jean-Paul Sartre. Aquinas, a thirteenth-century Dominican friar, and Sartre, a twentieth-century philosopher and atheist, are separated by both time and religious beliefs. Yet, for philosopher Joseph S. Catalano, the two are worth bringing together for their shared concern with a fundamental issue: the uniqueness of each individual person and how this uniqueness relates...