Commission, a body of Catholic theologians from around the globe, has stated in one of its most insightful documents, “The truth of revelation … is universally valid and unchangeable in substance.”2 But people often express uneasiness with Vatican II—at least in certain quarters of the church—because of the sense that the council “changed” Catholicism in significant ways. Identifying precisely what changed is often difficult. An obvious variation, of course, is the liturgy that is now celebrated