In The Dogma of the Immaculate Conception: History and Significance (University of Notre Dame Press, 1958; reissued 2016), thirteen European and American theologians treat the historical development and theological significance of a major Roman Catholic doctrine. Edward Dennis O'Connor, C.S.C., a specialist in mediaeval theology, notes in his preface that the subject of the Virgin Mary's Immaculate Conception was first discussed about the year 1100. The doctrine was defined by Pope Pius IX in 1854 after about seventy-five years of "what was perhaps the most prolonged and passionate debate that has ever been carried on in Catholic theology." The importance of any doctrine, however, "does not lie chiefly in its history, but in its intrinsic significance as truth, and in its rank in the hierarchy of truth, which do not depend on historical contingencies." From this point of view, the Immaculate Conception is of immense importance not only for Mariology but also for the theology of the Redemption and of the Church.The essays in The Dogma of the Immaculate Conception are broad-ranging studies both of the history of doctrinal development and the major aspects of the doctrine. The volume includes chapters ranging from "Scripture and the Immaculate Conception" to "The Immaculate Conception in Art," over fifty illustrations, and an exhaustive bibliography of the European literature on the doctrine published from 1830 to 1957.