George Weigel is author, most recently, of "Witness to Hope: The Biography of Pope John Paul II." Paul II."

By far the most fascinating piece of theology I've read in the 1990s is Servais Pinckaers's The Sources of Christian Ethics, first published in 1995 by the Catholic University of America and happily still in print, as it should be for decades to come. Pinckaers's analysis of the twists and turns in the Western idea of freedom is a reader-friendly tour de force with implications for just about every issue in American public life today. Most definitely not for theologians only.

Salt of the Earth: The Church at the End of the Century (Ignatius), a book-length interview with Cardinal Joseph Ratzinger, opens a window into the agile mind of one of the decade's most controversial and, to my mind, insightful figures.

Abraham Joshua Heschel: Prophetic Witness (Yale) is the first of a projected two-volume biography of the man whom Rabbi David Novak of the University of Toronto calls "the most significant Jewish thinker ever to live and work in America." David Novak's own new book, Natural Law and Judaism (Cambridge), is a large contribution to the dialogue at the "moral border" between Judaism and Christianity.

James T. Burtchaell's massive study, The Dying of the Light: The Disengagement of Colleges and Universities From Their Christian Churches (Eerdmans), is a major work of American intellectual history. And Richard John Neuhaus's Appointment in Rome: The Church in America Awakening is a lively look at Vatican goings-on, combined with a bold proposal for cooperation between Roman Catholics and Evangelical Protestants in the 21st century; the Pope liked it, which isn't bad as far as endorsements go.