Let us begin again, then, with the fundamentals.[i] The ultimate good that all human action seeks is happiness (or flourishing, eudemonia). This is the telos of human life, the end of all things. All of ethics, then, is situated with this as the focus: it is the study of how to attain happiness or fulfill our nature as persons. To use a medieval term, we are seeking the perfection of our natures. The way to achieve this is through activity of a certain sort, namely rational activity, in befitting with our natures as rational animals. This activity must be in accord with that which distinguishes us, and that is our function: a life of well-done action according to reason.[ii] This is why virtue and virtuous activity are important on a natural law account, as virtuous activity and possessing virtue simply are what fulfill the human function and bring about the flourishing of human nature. More specifically, virtue and virtuous activity is both that which allows one to grasp more clearly the basic principles of practical rationality, and thus allow one to act correctly, and also the efficient cause of the perfection of an individual’s very nature. Virtue brings one to be what he was meant to be.[iii] The principle is this: human flourishing consists in performing the human function well.[iv] Being a flourishing specimen, as it were, means fulfilling ‘what it is to be’ the sort of thing you are; this is the teleological aspect of natural law.
This leads to a concept that is not explicit in Aristotle, but which Augustine and later Aquinas will incorporate and make much fruitful use of; namely, the identity of being and goodness. This is known as the Convertibility Thesis, and it states two things. (1) Insofar as something exists (has being) it is good, and (2) it is good to the extent it actualizes its potentialities as a given member of its kind.[v] This provides a foundational point to ground goodness: existence is a basic good. Further, members of kinds (such as particular humans of the human kind) are good insofar as they actualise or become their natures. The ontological principle is to “be all that you can be!” Moral freedom will come to play an important role in this regard, given that we choose to act in ways that actually fulfill our natures, or not. This is, fundamentally, the concern of natural law. As Alasdair MacIntyre points out, in his After Virtue, the long history of natural law is to be traced to the underlying principle of a teleological scheme:
Within that teleological scheme there is a fundamental contrast between man-as-he-happens-to-be and man-as-he-could-be-if-he-realized-his-essential-nature. Ethics is the science which is to enable men to understand how they make the transition from the former state to the latter. Ethics therefore in this view presupposes some account of potentiality and act, some account of the essence of man as a rational animal and above all some account of the human telos.[vi]
What the natural law tradition, after Aristotle, will add to this grounding conception is the notion that there are also ordained laws, derived from nature, that can be promulgated as an ethical theory. More will have to be said on this particular subject when we turn to the epistemic side of natural law and the contentions found there. Let us now turn from a discussion of virtue ethics broadly speaking to natural law more narrowly speaking.[vii]
[i] Here I will merely state, rather than argue, what the Aristotelian and Natural Law understanding is.
[ii] Aristotle, 1098a15.
[iii] Josef Pieper makes a similar and poignant point about a virtue approach to ethics: “It is true that the classic origins of the doctrine of virtue later made Christian critics suspicious of it. They warily regarded it as too philosophical and not Scriptural enough. Thus, they preferred to talk about commandments and duties rather than about virtues. To define the obligations of man is certainly a legitimate, even estimable, and no doubt necessary undertaking. With a doctrine of commandments or duties, however, there is always the danger of arbitrarily drawing up a list of requirements and losing sight of the human person who “ought” to do this or that. The doctrine of virtue, on the other hand, has things to say about this human person; it speaks both of the kind of being which is his when he enters the world, as a consequence of his createdness, and the kind of being he ought to strive toward and attain to—by being prudent, just, brave, and temperate. The doctrine of virtue, that is, is one form of the doctrine of obligation, but one by nature free of regimentation and restriction. On the contrary, its aim is to clear a trail, to open a way.” In the preface to his The Four Cardinal Virtues, New York: Harcourt, Brace, and World, Inc, 1965, xi-xii.
[iv] Aquinas and theologically minded natural law scholars add that human excellence truly consists in the activity of knowing and loving God, given that it is God who completely fulfills our natures.
[v] DeYoung, Rebecca Konydyk, et al. Aquinas’s Ethics: Metaphysical Foundations, Moral Theory, and Theological Context. Notre Dame, Indiana: University of Notre Dame Press, 2009 (see pages 24-26 for a good discussion of these concepts).
[vi] MacIntyre, Alasdair. After Virtue. Notre Dame, Indiana: University of Notre Dame Press, 1984, (52).
[vii] And here I shall present a Thomistic view, that is, Thomas via Jacques Maritain.