Aquinas's Ethics: Metaphysical Foundations, Moral Theory, and Theological Context

one. The Metaphysics of Human Nature

one The Metaphysics of Human Nature The question of who we are—of what we are—lies at the heart of Aquinas’s account of happiness. We must understand what human beings are in order to see what they can do, and know what they are able to do before we can appreciate how they actually act. Only when we grasp the inner workings of human actions, moreover, can we fully comprehend how and why we should act—that is, the best sort of life we can lead. In this chapter we examine the place of human beings in the universe as a whole. We are rational animals, Aquinas claims, but how are we to understand this? What does it mean to be rational, and what difference does it make that we are animals with reasoning capacities? The fact that we are intellective organisms possesses enormous significance for Aquinas’s conception of human nature and of human flourishing. According to Aquinas, all of reality is ordered in an elaborate “hierarchy of being” with God at the top. Human beings alone possess both physical bodies and immaterial intellects; in the hierarchy we bridge the gap between material and immaterial creatures. In an important sense, we live in two worlds: the physical world of rocks and trees and the immaterial world of the intellect. Getting clear on human nature thus requires a closer look at the hierarchy of being in order to understand the place occupied by bodies and intellects in the broader context of God’s 13 nature and God’s relation to creation. As we will see, the structure of the hierarchy of being gives us insight into human beings both on a “species” level—as members of a common species, possessing the same essential nature—and on an individual level, as creatures who actualize this essential nature in different ways and to varying degrees. The Hierarchy of Being Aquinas believes that everything that exists has a place in the universe , and that its place follows directly from that thing’s relation to God. In saying this, of course, he does not mean that everything has a particular location in the universe. Rather, he means that every existing thing fits in a special way into a larger schema, and that God is responsible for this schema, or hierarchy. In his view, human beings occupy a particularly interesting place in this hierarchy (insofar as we alone possess characteristics of both material and immaterial creatures), but every creature has a special relation to God, and every creature has a particular place in the hierarchy. To see what is most interesting about the human case, first we need to focus not on the unique aspects of our nature but rather on how Aquinas frames that nature in the larger context of the hierarchy of being.1 It is essential to note that all creatures have their place in the hierarchy from their relation to God, and that all things depend on God both for their coming into existence and for their continuing to exist. According to Aquinas, the creator of the cosmos is not an impersonal force that merely put into motion the process that resulted in our world. Neither is God a personal but disinterested artisan who crafted the universe and then left it to its own devices, like a divine watchmaker or homebuilder. Instead, God is an all-powerful, all-knowing, and completely good Being who remains intimately involved in creation, constantly working for its good. God is the Alpha and the Omega—the beginning and end of everything that is, that was, and that will be. In other words, God is both the first cause of all things that exist and their final end, the very purpose for their existence. Aquinas endorses Augustine’s famous sentiment that our hearts are restless until they rest in God: everything receives its na14 Aquinas’s Ethics ture from God, and everything fulfills its nature only when it comes into right relation with God. This central belief can be seen in the structure of Aquinas’s bestknown work, the Summa theologiae, in which God is both the beginning and the end of the discussion; God is that which explains the existence, status, and function of everything else.2 Thus, Aquinas begins Part I of the Summa with a discussion of God’s nature, moving on to address how created beings...