Very few Catholics become vegetarians for moral reasons, and virtually no one would expect them to since vegetarianism seems to go hand in hand with views which are incompatible with the Catholic faith. The purpose of this paper is to show that the Catholic Church accepts principles-widely accepted by others, too-which imply a conditional, though broadly applicable, obligation to avoid killing animals for food. Catholic thinkers have not hitherto applied these principles to vegetarianism, but have long used them in other (...) ways. The case is built on texts from St. Thomas Aquinas and the Catechism of the Catholic Church. (shrink)