Brotherhood as an ideal has meant many different things. In this disarmingly simple study Ratzinger begins by examining two contrasting views: that of the ancient mystery religions which created 'closed ' brotherhoods of the initiated; and that of the Enlightenment, which looked to an open brotherhood of all. The author finds the first of these views too restricted and inward looking and the second too extended. After a brilliant exposition of New Testament teaching, he proposes a synthesis in which the Christian ideal of brotherhood is shown to be both 'restricted' and 'universal'. Essential biblical Christianity is once again shown to be more meaningful and more radical than most of us, Christian or non-Christian, imagine.