Evaluation

Evaluation

of Thomas Aquinas and John Duns Scotus on Natural Law

Aquinas’ writing is well organized, follows a logical path, and is relatively clear. He poses each of his questions in the form of an article, provides arguments for each possible answer, and then clarifies his own position. This organization is not only thorough, but helpful, and aids the reader in seeing both sides of the argument. His thoughts are surprisingly insightful for his time; it is no wonder he has been so influential on law and ethics.

That said, there are two flaws in Aquinas’ work that are pervasive. First, throughout his discussion on natural and positive law, he refers to “the commonweal,” or the public welfare. He writes that lawmakers make laws “to serve the commonweal” (Klima, et al., p. 370). He also writes that laws should only be revised when “their revision serves the commonweal” (Klima, et al., p. 371). But not once in any of these discussions does he define “the commonweal.”

Aquinas comes close in Question 94 of Summa Theologiae, where he lists a few of man’s good natural inclinations: the inclination to shun ignorance, to preserve oneself, and to reproduce. But he does not say whether these individual inclinations are also part of the common good, and if they are, how positive law relates to them.

Without a definition of the commonweal, it is easy to question positive law. Do income tax laws, for example, work for the common good? Governments could gain revenue without taxing individuals’ incomes, after all, so income taxes are not entirely necessary; and one could argue that income taxes are harmful to citizens, because they take money from citizens before they even have a chance to purchase their basic needs of food and shelter. Likewise, do laws banning public nudity work towards the common good? One could argue that it is not contrary to the good of society for a society’s citizens to be naked; nakedness in itself is not a bad thing. And what about gun-control laws – do they contribute to the common good? It could be said that they protect citizens by keeping firearms out of the hands of criminals, but it could also be said that they harm law-abiding citizens by preventing them from owning firearms for their own protection.

Clearly it is necessary to have a definition of the common good, because without one, the term becomes subjective. When the definition of “the common good” is left up to individual interpretation, it becomes easy to tear down existing laws and to add unnecessary laws. True, one could argue that these examples – income taxes, prohibitions on nudity, and gun-control – are for the common good, or, if they aren’t, that they are unjust laws that need to be revised. But a working definition of “the common good” is important if we are to continue making laws, and not just revise past laws.

Aquinas’ second fault is related to his first; he bases much of this work on the assumption of an ideal scenario – he assumes that lawmakers do, in fact, make laws for the good of society, rather than for their own self-interests or for the benefit of the lawmaking class. Furthermore, if the lawmakers are actually making laws that are unjust or not beneficial to the common good, it would be difficult to stop them – it is the lawmakers who revoke laws, and a corrupt lawmaker would not be likely to repeal his own ordinance.

Assuming that lawmakers serve the common good is particularly dangerous without a definition of the common good: a persuasive person could argue that almost any law, even an unjust one, is for the common good. In the twentieth century, for example, Adolph Hitler was persuasive enough to initiate programs of eugenics and genocide, which his government passed off as for the common good. He himself wrote that everyone “must subordinate his own interest to the common good” by helping consolidate the government and continue its programs (Hitler, 1945).

Aquinas’ arguments, while intelligent, would be stronger if he had defined the common good and considered the possibility of corrupt lawmakers. While he briefly mentions “unfaithful or unwise” rulers, he does so in reference to dispensations, which is not quite what is needed (Klima, et al., p. 374). The assumption that lawmakers work for the common good underpins Aquinas’ entire argument; his lack of discussion of corrupt or inept rulers leaves his otherwise perfect argument with a somewhat shaky foundation.

Like Aquinas, John Duns Scotus is also relatively clear for a philosopher. He, too, presents different viewpoints, arguing and refuting them before presenting his own thoughts. It is generally easy to understand his arguments and to follow his line of thinking. But he does have a few minor flaws in his arguments.

First, he begins his work on the Decalogue and natural law by defining natural law. He says that “the law of nature is either a practical principle known immediately from its terms or necessary conclusions that follow from such principles” (Klima, et al., p. 375). But this is a very vague definition, for what seems immediately obvious to one person might not seem immediately obvious to another. For example, while it may seem an obvious practical principle to the general population that child molestation is morally wrong, it may not be an obvious practical principle to a pedophile, who sees “loving” children as natural. Thus, the vagueness of Duns Scotus’ definition of natural law undermines the otherwise intelligent argument. This work would have been clearer if Duns Scotus had stated whether natural law is made up of practical principles as perceived by individuals or as perceived by the majority of society. While this may seem like an insignificant point to argue over, it is nonetheless a point that an opponent of Scotus’ could get his or her claws into. Duns Scotus’ work would be more solid if his definition of natural law were more specific and if more attention were paid to it.

Another point in Duns Scotus’ work that could be argued is his statement that “The other way in which things belong to the law of nature is because they are exceedingly in harmony with that law, even though they do not follow necessarily from those first practical principles…” (Klima, et al., p. 378). This statement directly contradicts his earlier definition of natural law, which says that a natural law is a practical principle or a conclusion drawn from such a principle (Klima, et al., p. 375). If Duns Scotus wanted to include things that are in harmony with natural law in the definition of natural law, then he should have done so; but after leaving these things out, it is bad form academically to include them later. Furthermore, just because something is in harmony with natural law does not meant that it is natural law – after all, according to Scotus himself, natural law is only either a practical principle or a conclusion drawn from such a principle, not something that is in harmony with such a principle. Duns Scotus seems to have shot himself in the foot with his definition of natural law.

Duns Scotus further weakens his argument by omitting what it means for something to be “exceedingly in harmony” with natural law. “In harmony” is a very vague and subjective phrase; without a concrete definition, one person’s idea of harmony may be different from another’s. Furthermore, Scotus refers to some things as “exceedingly in harmony” with natural law, yet he could not even clearly define natural law. Without a solid definition of natural law, it is impossible to form a solid definition of what is in harmony with natural law – therefore, it is impossible to be certain if something is or is not in harmony with the law of nature.

John Duns Scotus’ arguments would be stronger if he had given a more concrete definition of natural law, elaborated on what it means for something to be in harmony with natural law, and had refrained from contradicting his own statements.

Fortunately, these flaws do not entirely cripple the rest of his argument. His reasons for why the first table of the Decalogue belongs to natural law are generally quite logical. As he says, “If God exists, then he alone must be loved as God” (Klima, et al., p. 378). This is an obvious practical principle, because if God (the individual) exists, then he is the only God. One could argue that there might be other gods, but God is presumably the only God, just as – for example – John Smith is the only John Smith, one-of-a-kind because of his unique combination of physical characteristics and personality traits.

Duns Scotus’ arguments about the Ten Commandments are well thought-out – he even admits that the third commandment may not relate to natural law at all, and gives reasons why it might and why it might not. This style of discussion is not only helpful, but admirable.

Both Thomas Aquinas and John Duns Scotus present intelligent and persuasive arguments on natural law. Although their writings suffer from a few flaws, their arguments are for the most part thorough and astute, and it is easy to see why each has made his mark on philosophy.

Sources:

Hitler, A. (1945). My political testament. Retrieved November 26, 2007, from http://www.hitler.org/writings/last_testament/

Klima, G., Allhoff, F., & Vaidya, A. J. (Eds.). (2007). Medieval philosophy: essential readings with commentary. Malden, MA: Blackwell Publishing.

Helpful Links:

The entirety of Thomas Aquinas' Summa Theologiae online:

http://www.newadvent.org/summa/2.htm

jhdavis@smcm.edu

Site Last Updated: 11/01/2007