Anyone looking to understand the decades-long struggle between Catholic progressives and the late Pope John Paul II – who was aided in his conservative renewal by his theological wingman, Cardinal Joseph Ratzinger, now Pope Emeritus Benedict XVI – could do no better than reviewing the tale of French Bishop Jacques Gaillot. Gaillot was named bishop of the Diocese of Evreux, west of Paris, in 1982, in the early years of John Paul’s pontificate, and Gaillot quickly came to stand as a symbol of the sort of social activist bishop – and theological liberal – that the Polish pope sought to...