Post Author: Bill Pratt
In a 5-part series of posts, we looked at several metaphysical principles which all inevitably lead to the existence of God. Given these principles, and the existence of God, how do we go about constructing a Christian ethical theory? Or, more to the point, how does metaphysics help us identify the good for human beings?
A thing is good insofar as it instantiates its essence, and, particularly with living things, essence (formal causality) is tied to the thing’s purpose (final causality). To know what is the good for a human being, we must first look to the essence of being human, or human nature, and we must look to the purposes toward which human nature is pointed.
Notice that metaphysical naturalism is already in trouble. Metaphysical naturalists cannot appeal to “human nature” or “essences” or “final causes” within their ontology, as those aspects of reality simply do not exist for them.
The Christian, using classical Christian metaphysics, can affirm the existence of objective, transcendent moral values because the good for human beings is based upon objective, transcendent metaphysical principles: the formal causes and final causes of humans. How does the formal cause of humans, or human nature, determine the good for us? Edward Feser remarks, in Aquinas,
Knowing what is truly good for us requires taking an external, objective, ‘third-person’ point of view on ourselves rather than a subjective ‘first-person’ view; it is a matter of determining what fulfills our nature, not our contingent desires. The good in question has moral significance for us because, unlike other animals, we are capable of intellectually grasping what is good and freely choosing whether or not to pursue it.
There are three different categories of goods inherent to human nature. According to Feser, “First are those we share in common with all living things, such as the preservation of our existence. Second are those common to animals specifically, such as sexual intercourse and the child-rearing activities that naturally follow upon it. Third are those peculiar to us as rational animals . . . .”
The last category is the most important, as it is the highest aspect of human nature. The purposes of human beings include such things as survival, sexual intercourse, and knowing truth. These purposes are entailed by our human nature, which includes the fact that we are living, sexually reproducing, and rational beings; we are rational animals. As rational animals, however, what is our ultimate purpose? Put another way, what is the ultimate good for mankind?
We’ll look at the answer to that question in part 2.