Thomas Aquinas and Natural Law I
Prof. Bill Long 9/20/05
The purpose of this and the next four essays is to exposit leading themes in Aquinas' treatment of the purpose of law in questions 90-97 of Part I (of the Second Part) of his Summa Theologica (ST). I will only be focus on aspects of Q's 90-92 and 94-95. In this essay I will lay out some influences on Thomas and describe his method, give an overview of these five questions and then begin an exposition of Q. 90.
Influences on Aquinas (1224-1274); His Method
Though he frequently quotes Isidore of Seville (ca. 560-636), he is largely indebted to three older sources: Aristotle, the Bible and Roman law. To Aristotle he owes the crucial distinction between speculative and practical knowledge, the teleological view of humanity (that our aim is happiness) and the role of God as first cause. To the Roman jurists he owes the distinction between and among three kinds of law: ius civile, ius gentium (a sort of international law) and ius naturale (taken from the Roman Stoic philosophers). His reliance on Stoic philosophy explains his commitment to reason in human affairs and the role of reason as fundamental in the shaping of human law. Finally, he often quotes the Bible to illustrate his points. The Bible can never be refuted but often can be supplemented by the role of reason. Thus, if God commands someone to commit adultery, it is permissible only for that person and occasion simply because it is the command of God, but such a command would never become part of the natural or civil law of a society.
In arranging his enormous treatise (ST), written over a 9-year period near the end of his life, he follows a predictable five-part method. (1) He will raise a question that he wants to exposit (e.g., whether law is something pertaining to reason?); (2) He then gives two to four objections, or answers to the question which ultimately will not be his answer. These objections are often introduced by or dependent on a quotation from one of his beloved authorities. By so doing, he is setting up a sort of disputation in which he is the only speaker; (3) The "sed contra" follows, in which he states his approach in a nutshell (e.g., "On the contrary, It belongs to the law to command and to forbid. But it belongs to reason to command as stated above (q.17, A.1) Therefore law is something pertaining to reason"); (4) He proceeds with his "answer," in which he gives support to the "sed contra" in more detail; (5) He replies to the objections raised. Each reply objection is keyed to the corresponding objection raised in the first part. Thus, if you want to get to the "heart" of Aquinas, meaning his conclusions, you simply check out the "sed contras" and his "answer," though if you would like to see the full range of his debate-oriented mind, you also might on occasion work through the objections and replies.
An Overview of the Section
Thomas' treatise on law occurs in the First Part of the Second Part of ST. In this Second Part Thomas looks at human acts, which he divides into intrinsic and extrinsic acts. When he gets to extrinsic acts (Q.70), he begins his treatment with sinful human action (Q's 70-89) before talking about virtuous action. Virtuous action is stimulated by the law and enabled by God's grace. Thus, he first needs to deal with how law helps in the life of faith. His first task, then, is to understand what law is and how it functions. He does this in Q's 90-97. Within 90-97, a further distinction can be made. Q's 90-92 are more "methodological," in which he deals with: (1) the essence of law (90); (2) the different kinds of law (91) and (3) the effects of law (92), while Q's 93-97 deal with three of the four kinds of law mentioned in Q.91. That is, Q. 93 treats the eternal law, while Q.94 focuses on natural law and Q. 95 deals with human law. Instead of having Q's 96-97 treat the fourth kind of law (divine), Aquinas continues reflecting on the nature of human law in 96-97. Q.96 treats of the "Power of Human Law," while Q.97 handles the "Change of Laws." Only in Q.98 does he begin to probe the fourth kind of law (divine law), which he then discusses for several questions.
Question 90: Of the Esssence of Law
I will go through Article 1 of this question with a little more care than subsequent questions because I want us to see his method at work. Question 90 is divided into four articles that each have to do with the essential nature of law. Thomas is brilliant because he will pose questions, come up with extensive definitions and "answers" to his questions and, finally, conclude the section with a statement that perfectly ties up the leading point made in each article. Because of Thomas' emphasis on the value of human reason, we know the answer to the first question even before he starts to answer it. "Whether Law is Something Pertaining to Reason?" is the way he frames it. The three objections he raises are derived from biblical and legal sources. From St. Paul he quotes a verse suggesting that law may be in "our members," (i.e., our sensual or bodily self), and since reason, for Thomas, has nothing to do with this sensual self, law must not have to do with reason. Second, he draws upon his earlier discussion of the intellectual virtues to sugest that power, habit, and act (which constitute reason) are not the essence of law. This point is obscure unless you are steeped in Thomas; I will therefore pass on. Third, he argues, from a Roman authority, that law petains to the will because it moves those who are subject to it to act aright. Since the will is distinct from the reason, law cannot be an act of reason.
Then follows the "sed contra" where Thomas lays out his approach. Law commands and forbids. But he has previously argued in Article 1 of Question 17 ("Whether Comand is an Act of the Rason or of the Will?"), relying on the authority of Gregory of Nyssa and Aristotle, that since even the appetite obeys reason, command is an act of the reason. And since commanding also includes the concept of forbidding, law is something that belongs to reason. But then, in his answer, he goes into more detail about the nature of law. Law is "a rule and measure of acts, whereby man is induced to act or is restrained from acting." Law is thus like a yardstick, both giving us the extent of what needs to be obeyed as well as giving us a way by which we can measure our conduct. Then, quoting an earlier section of his work, which provides that reason is also the rule and measure of human acts, he concludes that law is something pertaining to reason.
There is only left for him to reply to the various objections. To the biblical one he makes a distinction between something that shares the essence of a law and something that only "participates" in it. When St. Paul talked about the law of the members, he was only referring to the latter. He answers the second objection by distinguishing between speculative and practical reason, and the third he answers by quoting his earlier treatment of the acts commanded by the will (Q.17) to show that reason derives its power from the will but in order for the will itself to have the force of law, it must be in accord with some rule of reason.
Just to let you know, we have only gone through one article (of four) of one of the eight questions on the Aquinas' understanding of law. From this discussion, then, we learn that law is an ordinance of reason.
Copyright © 2004-2007 William R. Long