What we mean by “law” is a question germane both to religious and political philosophy. In some sense, it just seems to mean “necessity”. This seems to be the usage in Romans 7:23, where Paul talks about “another law” in his members waging war against the law of the Lord in his inner being: his human nature is still by necessity bound to sin – the “law” of sin.
But other times it seems to be invested with much more meaning than simply necessity. Legally and politically, it refers to the coercion exercised by a political sovereign. Though this might seem at first glance to describe the law of God as well as the law of man, the authority of God is exercised in an essentially different manner from political authority. Indeed, “The Law” talked about in the rest of Romans 7, the moral and ceremonial law from which the Christian finds himself freed, can seem so unlike human laws, that attempts to invest the word with more meaning can seem doomed from the outset to conclude the two are totally separate things, unfortunately described by the same word.
This is the case with Aquinas’ conception, by which “a law implies order to an end” (Summa Theologica 91.1). Laws direct us, accordingly, to various ends, and the justice of a particular law lies in the degree to which its ends comport with those of natural law – i.e., so far as it “foster religion, be helpful to discipline, and further the common weal” (Summa Theologica 95.3).
This definition depends on Aquinas’ marriage of Catholic to Aristotelian political philosophy, in which virtue is the end of the polity. Law, according to Aristotle, directs men towards virtue. This fusion persists to this day in Catholic social doctrine.1 Aquinas cites Aristotle to assert that no individual can, but the polity may, coerce people towards virtue (Summa Theologica 90.3). Since virtue is constituted by proper ends,2 and laws are coercion, people may be coerced into virtue.
The incompatibility of the Aristotelian framework with Christian thought can, however, be easily shown from scripture.
For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh, so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit.
The essential point of this passage is that the law (here referring to what Aquinas would call the Divine Law) has no power to direct us towards ends. Psalm 19:7 says “The Law of the Lord is perfect”. If the very perfection of Law is too weak to direct us towards proper ends and deliver us from condemnation, how much less does human law have any such power?
The essence of law is not to direct men towards other ends, for it has no such power. Rather, law takes a means, and elevates it to an end in itself. Though a law may point towards a higher end, it cannot itself be effective towards that end, and this is exactly why law is itself insufficient for salvation.
This was the problem complained about in Isaiah 1:11-15. Israel multiplied sacrifices and conscientiously observed the feast days, but they were content with the law, needing no God. They prided themselves on the simulacrum, neglecting the reality. This was also the problem of which Jesus accused the Pharisees: they kept the law to the letter, but on the inside are dead men’s bones (Matthew 23:27). In both cases, the law was treated as an end in itself, for that is all the law can be in itself. What are properly means towards the highest end became hollow as ends in themselves.
But the insufficiency of the moral law for salvation is also exactly the kind of flexibility necessary for political law. The laws on the books against murder proscribe certain means – i.e. killing people – to point to the ultimate end of avoiding unnecessary death. Now such laws do not demand a pure love from everyone. Indeed, a man could carry on with the most seething hatred towards his fellow man, and unless he actually attempts to kill someone, the law has no quarrel with him. Clearly the law cannot direct him to the higher end of valuing human life, but it can approximate the behavior as if he held those values, by compelling him to hold the avoidance of murderous means as an end itself.
Milton Friedman speaks of the elevation of means to ends in his book Capitalism and Freedom (ch. 2):
Any end that can be attained only by the use of bad means must give way to the more basic end of the use of acceptable means.
The manner in which these elevated ends point to a higher end leads us to a conception of justice. Satisfaction in life comes from arranging a constellation of independent and sometimes conflicting ends into a structure in which all ends point to an ultimate end (and more than that, the consummation of that ultimate end). In the same way, a just series of laws will point to the same end. Not virtue, as if the law could save anyone, but love. Though the law is incapable of effecting love (and love certainly cannot be required as such by the law), such laws as point to love will serve to engender social peace and economic order by allowing people to rely on others as if they were honest and benevolent.
Departure from a single principle in lawmaking, on the other hand, leads to rent-seeking (i.e. the preferential treatment of one person or group before the law) and unprincipled expansion: if the power is there, it will be taken advantage of. And it is through this process that the potentiality of injustice, exhibited in the design of institutions, is made manifest in actual acts of injustice which aggravate social peace and smother economic order.3