The Role of Teleology in the Moral Species
Jensen, Steven J., The Review of Metaphysics
IT IS DIFFICULT TO AVOID THE CONCLUSION that teleology plays a central role in Aquinas' ethics. Even the new natural law theorists, such as Finnis and Grisez, who have eschewed teleology within ethics, opting instead for a kind of practical intuition of moral norms, have conceded a link between a normative human nature and the human good. As Christian thinkers, they must acknowledge that God has made us for some purpose, and this purpose is pivotal for the human good. Their rejection of teleology is relegated to the domain of epistemology, that is, they deny that we become aware of the human good by first becoming aware of certain natural teleological inclinations; instead, they claim that we first become aware of the good, and thereby recognize our human nature with its teleological inclinations. I am not presently concerned with the implications of this view, for I inquire only into the role of teleology for the good and evil of human actions; the manner in which we become aware of this role and of this teleology is beyond my purpose. I wish, rather, to investigate two possible roles that teleology might play in the ethics of Aquinas.
That Aquinas sees teleology as essential to the good and evil of human actions is most evident in his treatment of sexual sins. In the De Malo, for instance, he is particularly straightforward.
All human acts are said to be disordered when they are not proportioned to the proper end. For example, eating is disordered if it is not proportioned to the health of the body, to which the act of eating is ordered as to an end. Since the end of using the reproductive organs is the generation and education of offspring, every use of these organs that is not proportioned to the generation of offspring, and to their due education, is of itself disordered, for example, every act of these organs outside the union of male and female is manifestly unfit for the generation of children. (1)
Aquinas has in mind some natural teleology as opposed to some human generated endpoint, for in the reply to the objection that fornication can be done for some good end, Aquinas says,
The end of the act itself is ordered according to its very nature, even though the intention of the agent might be for a good end, which is not sufficient to excuse the act, as is plain in one who steals intending to give to charity. (2)
This end of nature shows up again in the very next reply. "Every voluntary emission of semen is illicit unless it is suitable for the end intended by nature." (3)
Aquinas presents us with a teleology that serves as a standard of human actions. Teleology defines what is good and proper; our actions must live up to it. For instance, since sexual actions are ordered to new life they are good and perfected when they live up to this order. An act of bestiality, since it fails from this direction to new life, is an evil action. In the following text, Aquinas presents this teleological worldview as a standard for all virtue.
Virtue is a certain disposition of what is perfect. I call something perfect, however, when it is disposed according to nature, from which it is plain that the virtue of anything is said in order to some preexisting nature, namely, when everything is disposed insofar as it is fitting to its nature. Plainly, however, the virtues acquired through human actions, which were discussed above, are dispositions by which someone is fittingly disposed to the nature by which he is a human being. (4)
Virtue must be properly disposed to human nature, with its natural ends and perfections; in contrast, sin opposes the natural purpose and teleology of human nature. As I have already suggested, it is difficult to contest this normative role of teleology within Aquinas's ethics. I am, however, more concerned with another possible use of teleology, suggested in one text of the Prima Secundae. …