Walter Kasper (born 5 March 1933) is a German Roman Catholic Cardinal and theologian. He is President Emeritus of the Pontifical Council for Promoting Christian Unity, having served as its president from 2001 to 2010.
A good, sometimes dense but precise and readable book on the theology of marriage. A short book but Kasper can really fit in the essentials with a few gems of reflection. Particularly valuable, I think, was his discussion of the indissolubility of marriage and its pastoral implications.