 The central difficulty with this employment of the master rule approach is that of explaining how we are to grasp this first principle of morality as correct. What is the relationship between our knowledge of the basic goods and our knowledge of the master rule?  When Grisez defends his master rule, he writes that its status is due to a certain function that a first principle of morality must perform:  “It must provide the basis for guiding choices toward overall human fulfillment. As a single principle, it will give unity and direction to a morally good life. At the same time, it must not exclude ways of living which might contribute to a complete human community” (Grisez 1983, p. 184). But this presupposes an awful lot: why should we assume in advance that a proper response to the basic goods must be one that is oriented toward a “complete human community”?