The republication of We Hold These Truths is but one indication of the continuing importance of the thought of John Courtney Murray for the Catholic Church in the United States. More than any other American theologian in this century, Fr. Murray developed a new understanding of the healthy relationship between religion and politics, church and state, in a democratic context. Until now, however, the evolution of Murray’s own thought in these matters has not been fully understood. Beginning with Murray’s first forays into the public arena in the 1940s, Leon Hooper carefully plots Murray’s movement away from the classical concepts of conscience and rights toward a more historical understanding of moral agency and of the church’s necessary engagement with a pluralistic world. Along the way, Fr. Hooper reveals in detail for the first time the importance of Bernard Lonergan’s thought in moving Murray toward and then beyond his vital contribution to Vatican II’s Declaration on Religious Liberty .