ethical theory discussion

In the Summa Theologiae, Aquinas's magnum opus, he defines law as an "ordinance of reason for the the common good by one competent to make it and promulgated (ST I-II,Q.90). He further distinguishes between the eternal law which comprehends God's providence and the physical laws of the universe, natural law which is God's will for human beings communicated by reason, human law which is given by legitimate authority for the human good and must be consistent with the natural law for legitimacy; and finally the divine law which directs humans to their supernatural end (salvation) (ST I-II,Q91.5).

While his full theory sees humans' final end as theologically informed, Finnis argues that Aquinas's moral theory is detachable from and prior to his theological treatment of perfecta beatitudo (perfect happiness) (Finnis 3). I will follow his interpretation here and concentrate on his natural law.

Aquinas recognizes the seemingly unresolved tension in Aristotle between the final good as a life of (practical activity according to reason) and contemplation. He attempts to spell out the first principles of ethics without making assumptions about the final unitary end of human beings(3).

The fundamental principles in the decalogue (10 commandments) are, for Aquinas, discoverable and knowable by human reason independently of that revelation through which they are given in scripture. This revelation, however, confirms and clarifies them (4). In an important sense, then, for Aquinas, the fundamental principles of morality are universal and self-evident (to the wise). His position, then, is a rejection of such views as ethical relativism and subjectivism.

Thomas argues that just as theoretical knowledge is based on the principle of non-contradiction (that the same thing can't be both true and false at the same time in the same respect), practical reason is based on the principle of the good: "And as being is the first thing that without qualification falls within the understanding, so good is the first thing that falls within the understanding of practical reason. And practical reason is ordered to action, since every efficient cause acts for the sake of an end, which has the nature of good. And so the first principle in practical reason is one based on the nature of good, namely, that good is what all things seek. Therefore, the first precept of the natural law is that we should seek good, and shun evil. And all the other precepts of the natural law are based on that precept, namely, that all the things that practical reason by nature understands to be human goods or evils belong to precepts of the natural law as things to be done or shunned"(ST I-II Q.94.2).

Aquinas goes on to say that reason understands to be good all those things that we have a natural inclination for. This has lead some commentators to accuse him of "trying to derive an ought from an is". Finnis, on the other hand, provides a more sophisticated interpretation of Aquinas here. For one, Aquinas is not arguing that "Kantian structures of the mind" are what determine normativity. Rather it is the fact that parts of the world are a certain way, namely genuinely desirable, that we see things as choiceworthy or not choiceworthy (Finnis 6). Furthermore, since for Aquinas the fundamental goods are undeduced it is clear that they are not "oughts" deduced from any "is" (6).

In Question 94.2 Aquinas mentions 4 basic goods: Life, marriage between a man and a women and upbringing of children, knowledge and sociability.

For Thomas these goods are self-evident to the wise or those with experience. So with sufficient experience of what these goods entail we will naturally see them as choiceworthy. For instance, that a triangle's interior angles add up to two right angles is self-evident to the wise or the experienced but not everyone has this experience or wisdom (ST I-II Q.94.3).

Finnis gives the example of knowledge. As children we often have a strong curiosity about the world around us and ask our parents numerous questions. If we receive an adequate answer we feel satisfaction but if we don't then we are frustrated: "At some point one comes to understand-- has the insight-- that such answers are instances of a quite general standing possibility, namely knowledge, coming to know and overcoming ignorance. By a distinct though often well nigh simultaneous further insight one comes to understand that this-- knowledge-- is not merely a possibility but also a good [bonum], that is to say an opportunity, a benefit, something desirable as a kind of improvement (a perfectio) of one's or anyone's condition (Finnis 6).

This last point is significant, for seeing certain opportunities as choiceworthy goods, self-evidentally desirable, does not imply that Aquinas is advocating egoism (the ethics of self-interest) or arguing that reason is merely prudential (directed only at one's own self-interest), for one sees that these goods are goods for anyone. Some of the goods, such as friendship, even require that I see my friend as valuable for his own sake (7).

One question is how one goes from Aquinas theory of value (axiology), the fundamental values, to our specific duties (deontology). Finnis argues that this is done through the supreme moral principle of "love of neighbors as self". Again this is not an inference, from various "is" statements but rather a redescriptive summary of the set of the fundamental values (8).

Furthermore, the principle of "Love of neighbors as self" has a tight relationship to the golden rule "do unto others as you would have them do to you". So love and justice are intertwined here. My neighbor is potentially anyone in the world. In his fuller version of the love principle Aquinas would include love of God. But since the existence of God is not self-evident he allows for the more self-evident principle: love of neighbors as self. Interestingly, though, love of God is specifically violated by failing to love neighbors and self (8).

Moral norms are derived from the fundamental goods by seeing that the fundamental goods as genuinely choiceworthy exclude various acts which would treat them as if they were not fundamentally good. For instance, if life is a self-evident good then murder is clearly a violation of this value and thus something to be avoided.

Aquinas does allow for the possibility of justifiable lethal force in his account of self-defense and just war (see for instance ST II-II Q. 40, 64). Interested students should look to these sections for Aquinas's remarks on permissible killing and his doctrine of double effect.

We will conclude with responses to a few objections. We have already shown, following Finnis, that Aquinas is not guilty of "deriving an ought from an is" and does not advocate egoism.

Other objections can be seen in the form of relativism: do all cultures have the same fundamental values? Aquinas believes that they do. Although the particular applications vary. He also argues that the natural law can be changed by addition but not by subtraction, that is, we may find it necessary to add further self-evident goods to our list, but we may not subtract a self-evident good or obviously it wasn't self-evident in the first place (ST I-II Q94.4,5). Some object that Aquinas places too great of an emphasis on the biological values: life, and sexual union. I have nothing to say to this here however. Another objections requires clarification of how we are to treat the fundamental values; that is should we maximize them as a consequentialist would. Finnis and others develop responses to this objection.

In conclusion, through our brief introduction to his ethics here, I hope it has become clear that Aquinas, though known as a Christian Aristotelian, in many ways goes beyond Aristotle in important and interesting ways.