 Paradigmatic views in the natural law tradition starting with Aquinas hold both that the laws of morality have their source in God, and that these laws constitute the principles of human practical rationality (Finnis 1980; MacIntyre 1999). Views in this tradition may be seen as using the basic schema for definitions of morality in the normative sense, understanding endorsement as acceptance. Members of this tradition typically hold that all rational persons know what kinds of actions morality prohibits, requires, discourages, encourages, and allows. It is central to Aquinas’s view that morality is known to all those whose behavior is subject to moral judgment, even if they do not know of the revelations of Christianity. This is why Aquinas holds that knowing what morality prohibits and requires does not involve knowing why morality prohibits and requires what it does.