Audio file

Aquinas on Law, Happiness, and the Political Common Good

By Dr. John J. Goyette
Tutor, Thomas Aquinas College
Seventh Annual Conference on the Social Doctrine of the Church
June 20, 2015


I want to speak to you about the importance of human law, especially the important place that law has in our pursuit of the common good, which Aristotle and Aquinas identify as communal happiness, or the shared life of virtue. In Aquinas’s On Kingship he says that the civitas, or political community, comes together for the sake of living virtuously, something that can only be attained by living with others in a political community directed by the same laws and the same government to live well. Aristotle makes the same claim near beginning of his Politics and does so even more forcefully than St. Thomas. After asserting that man by nature is a political animal, he says this: “The one who first founded the polis [or political community] is the greatest of benefactors, for just as man is the best of animals when perfected, when separated from law and the administration of justice is the worst of all” (Politics I.2, 1253a30-32).

One might be tempted to adopt what might be described as a libertarian view of law and government, that government should not be concerned with making its citizens morally virtuous, but should instead concern itself with a more limited and instrumental good. On this view, human law and government are necessary only as a safeguard against violence and crime, or to secure some sort of economic prosperity. This is certainly not the view of St. Thomas Aquinas, who repeatedly insists on the role of human law as a moral teacher and guide. My aim is to briefly sketch for you three reasons why, for Aquinas, human law is necessary to lead men to virtue, or the life of virtue.

Let us begin by noting that law functions in different ways depending on the persons on whom it is imposed. Aquinas points out that law is imposed on two kinds of men and moves them in different ways. Consider the following texts:

Every law is imposed on two kinds of men. For it is imposed on certain men that are obstinate and proud, who are restrained and tamed by the law; it is also imposed on good men who, instructed by the law, are helped to accomplish what they aspire to do.1

Every law is given to some people. But in the people are contained two kinds of men: some prone to evil, who must be coerced by the precepts of the law, as stated above, some having an inclination to the good, either from nature, or from custom, or rather from grace; and such men must be taught and moved toward better things, by the precept of law.2

In addition to restraining those who are unruly, the law serves as a moral teacher to those who are well disposed. One might be tempted to put the emphasis on the need for the coercive power of law to restrain the violent or unruly. This is obviously important and necessary, but for Aquinas law is principally a work of reason: it belongs to the very definition of law to be a work of reason, whereas coercive power is something secondary, made necessary by those who do not cooperate with the intention of the legislator.3

Aquinas stresses the rational character of human law when he first discusses human law in q. 91, a. 3, where he draws a parallel between the speculative and practical reason in order to manifest the nature and necessity of human law:

Just as in the speculative reason, from naturally known indemonstrable principles are brought forth the conclusions of the various sciences, the knowledge of which is not imparted to us by nature but discovered through the efforts of reason, so also from the precepts of the natural law, as from general and indemonstrable principles, it is necessary that human reason proceed toward certain more particular arrangements. These particular arrangements [particulares dispositiones], devised by human reason, are called human laws, provided the other essential conditions of law be observed, as stated above.

Just as the sciences develop over time as a work of human reason, so is human law a work of reason. No science is developed, no art perfected, in a single generation, by one man alone. The development of the arts and sciences requires the cooperation of a multitude of men working together, each man passing on what he has learned to the next generation. It also requires the efforts of those who are wise to synthesize the collective experience of prior generations so that the arts and sciences can be perfected. The collective effort required for the development of the arts and sciences is, for Aquinas, one of the reasons why man is a political animal.4 But the same is true of human law: it a collective effort requiring experience and time, and the wisdom of the wise. Just as men perfect the arts and sciences as part of a community, so do men perfect their knowledge of the natural moral law by participating in the civitas.

Aquinas distinguishes two ways in which human law is derived from the precepts of the natural law, either as conclusions (conclusiones) or as determinations (determinationes).5 The first is akin to the way that conclusions are derived from indemonstrable principles in the speculative sciences, and in this way the precept prohibiting murder is derived as a conclusion from the more general precept of the natural law that “one should harm no man.” The second way that human law is derived from the principles of the natural law is akin to the way that the arts particularize or determine certain general forms, e.g., the way that a house builder must determine the general form of a house to some particular form. In this way, a human law specifying the punishment for a particular crime is a determination of the general precept of the natural law that “evildoers should be punished.” The determination that a criminal should be punished in this way, e.g, by a fine, or imprisonment, or exile, is not derived as a strict conclusion from the general precept of the natural law because the criminal can be justly punished in more than one way. Therefore, the determinations contained in human law have their force from the power of human law only, whereas things derived as conclusions, such as the prohibition against murder, have their binding force from both the natural law and human law.

The broader point, however, is that human law is essential for living the good life because it makes the general precepts of the natural law more specific. Moreover, the specifications of the natural moral law that human law provides are by no means obvious or self-evident, but are the work of experience and time, and are perfected by the prudence or practical wisdom of the legislator. Indeed, Aquinas asserts that law is the work of a special kind of prudence, what he calls “regnative prudence” [i.e., the prudence of the king or ruler], and this virtue is the most perfect kind prudence.6

The prudence or practical wisdom embodied in the law can be easily overlooked, and this is where the parallel between human law and the development of the arts and sciences is especially helpful. We tend to take for granted many of the moral precepts of the natural law as if they were self-evident, but we fail to notice that these precepts came to be known slowly over time by the development of human law. Most men now consider it evident that slavery, polygamy, and infanticide are morally wrong, but these very things were almost universally accepted and practiced in the ancient world. This is similar to the way we now accept as obvious scientific conclusions that were centuries in the making, for example, that the earth revolves around the sun and is not at rest at the center of the world, that the motion of the tides is caused by the moon, and that light travels. Hence, it may seem that the moral law is sufficiently evident that individuals and families can pursue the life of virtue on their own, but this view fails to consider that the moral principles adopted by individuals and families are largely the result of the moral direction provided by human law. It is often said that the family is the building block of society, and so it is, but the family on its own is not sufficient to live the good life apart from the moral foundation provided by human law.

Indeed, the insufficiency of the family to live the virtuous life apart from the civitas is perhaps most apparent when we consider the harmful consequences that result from the corruption of human law. The deleterious effects of no-fault divorce and legalized abortion show that the family cannot sustain itself without the direction provided by rightly ordered human law. Or, to take a couple of more recent examples, think about how quickly our opinions about gay marriage, physician-assisted suicide, and smoking marijuana have changed. Why is this? It is because we tend to look to the law as a kind of moral guide or teacher. If law the permits certain kinds of actions, we tend to think that they are good, or at least that they are only minimally bad. Similarly, if the law commands certain things, we tend to think that those things are good.

One might object, however, to this conclusion. Granted that the determinations (determinationes) of the natural law depend on prudent human legislators, since these sorts of things exist by convention rather than by nature, and require something like the skill of the artist, one might wonder whether the conclusions (conclusiones) of the natural law, those things that belong by nature to the moral life, necessitate the prudence of the legislator. If, as we have argued, the knowledge of the natural law depends on human legislators, have we not vitiated the natural law? Isn’t the whole point of natural law that the practical principles of the moral life are available to everyone and that those who are well intentioned can simply be guided by the natural law in their own private lives and have no need for human law and government as a moral guide?

According to Aquinas, most men left to themselves are capable of seeing only the most general precepts of the natural law and must rely on others, those who are wise, to know the remote conclusions of the natural law. Most men, for example, are capable of knowing the precepts of the Decalogue, for example, Honor thy father and thy mother, Thou shalt not kill, and Thou shalt not steal, since the reason of everyone judges at once that these sorts of things should be done, or not done, and Aquinas says that these things “belong to the law of nature absolutely.”7 But some moral matters are more difficult to see, and require wisdom and careful reflection: “The judgment of some matters requires much consideration of diverse circumstances, and not just anyone can carefully consider these things, but only the wise, just as it does not belong to everyone to consider the particular conclusions of the sciences, but only to the philosophers.”8

Hence, these more remote conclusions of the natural law derived by the wise must be taught to the less wise: “There are certain precepts which the wise, after a careful consideration of reason, judge should be observed. And these things belong to the law of nature, yet they require teaching, the wise teaching the less wise, such as Rise up before the hoary head, and honor the person of the aged man, and other such things.”9 For Aquinas, it is part of God’s providence that men are instructed in the natural law by means of the wise, by human legislators.10 The natural law is in principle knowable by reason even though the more remote conclusions can only be grasped by the wise after careful reflection, and are then communicated to the rest of mankind by means of human law. And since the natural law is “nothing other than the rational creature’s participation in the eternal law,”11 we might say that the highest function of human law is to enable every member of the civitas to participate more fully in the divine government. Indeed, this explains why Aquinas insists that human law and government would have been natural to man even apart from original sin, since even in his prelapsarian state men would have been unequal in knowledge and virtue and those who were wiser would have ruled their inferiors.12

While the role of law as a moral teacher is essential to law, it is not the only or even the most obvious reason why men need human law and government. This is why Aquinas also emphasizes the need for law to restrain the passions of those who are unruly. In q. 95, a. 1, he argues that parental authority is insufficient to lead men to virtue because some juvenile children are beyond the disciplinary power of their parents and need to be restrained by the coercive power of law:

As to those young men [iuvenes] who are inclined to acts of virtue by a good natural disposition, or by custom, or rather by a divine gift, paternal discipline suffices, which is by admonitions. But because some are found to be depraved, and prone to vice, and not easily moved by words, it was necessary that they be restrained from evil by force and fear, in order that at least they might desist from doing evil, and grant others a quiet life, and that they themselves, by being habituated in this way, might be led to do willingly what before they did from fear, and thus become virtuous. Now this kind of discipline, which coerces through fear of punishment, is the discipline of laws [disciplina legum]. Whence it was necessary for peace and virtue that laws be framed since, as the Philosopher says (Polit. I, 2), “as man, if he be perfect in virtue, is the most noble of animals, so, if he be separated from law and justice, he is the worst of all.”13

According to Aquinas, the discipline of laws is necessary to address a problem internal to the family, the insufficiency of paternal power to restrain the passions of youth. The young not only have strong concupiscible appetites inclining them to pleasure, they also have intense irascible appetites that incline them to be insolent or rebellious.14 Therefore, there needs to be some authority that inspires a kind of awe beyond paternal authority to restrain the passions of youth and to move them toward virtue.

Aquinas will note later that because the majority of men are imperfect, human law must move men toward virtue gradually, focusing especially on restraining or prohibiting those vicious actions that harm others and threaten to disturb the peace.15 The discipline or moral training provided by human law is a lengthy process. So the necessity of the coercive power of law to restrain the young, or those moved by their passions, is not a temporary or limited problem. The battle with concupiscence and the irascible appetite begins with puberty, but it does not disappear once children pass through the teenage years. Thus, the need for human law stems from the nearly universal difficulty of taming the passions, and the insufficiency of paternal discipline to cope with this problem. Hence, we see that the family is not self-sufficient with regard to living the life of virtue since paternal power is incapable of directing all men toward virtue.

Granted the insufficiency of paternal power to restrain the passions of youth, one might be tempted to place the emphasis in this passage on the need to use coercive power to maintain peace. Aquinas certainly makes that point, but his main point is that the moral training within the family is insufficient, and that the fear of civic punishment is necessary to lead the young toward virtue. The discipline of laws, therefore, has a twofold purpose. The ultimate end is to produce virtue, but it is also ordered toward a more proximate or intermediate end, to maintain peace.

We have shown that for Aquinas the wisdom and experience embodied in human law functions as a moral teacher for those who are well-intentioned, and that the coercive power of law is necessary to discipline the unruly, but there is an additional reason why human law is necessary that pertains to the actual administration of punishment, to the exercise of retributive justice. Aquinas, however, gives a threefold reason why the execution of justice should, as much as possible, be determined by law:

As the Philosopher says (Rhetoric I.1, 1354a32ff), “it is better that all things be regulated by law, than left to the decision of judges” and this is for three reasons. First, because it is easier to find a few wise men who are sufficient for imposing right laws, than to find the many men required to rightly judge individual cases. Second, because those who establish laws consider after much time what ought to be imposed by law, whereas judgments about individual actions are made from cases that have arisen suddenly; but man is able to see what is right more easily from the consideration of many cases, than from any one action alone. Third, because legislators judge in the universal and about future events, but human judges judge about present things, toward which they are affected by love, hatred, or some cupidity, and thus their judgment is perverted. Therefore, because the animated justice of the judge is not found in many men, and because it can be distorted, therefore it was necessary, whenever possible, that law determine what judgment should be made, and that very few matters be left to the decision of men.16

Because law is the result of the wisdom and careful reflection of the legislator, and because human law as such is abstract and impartial, restorative justice should be determined by law and not by the animate justice of the judge. Again we see Aquinas emphasize that law is a work of reason, a product of wisdom and experience, free from the passions of the moment, a more perfect participation in divine wisdom than the necessarily hurried, and passionate, judgments of individual men.

Let me focus on the last reason, the impartiality of law, since that is perhaps the most significant of the three reasons that Aquinas gives. It is because the rule of law is dispassionate, because law is reason free from passion, that punishments causing irreparable harm are altogether different from the crimes that they punish. It is precisely the rule of law rather than the rule of men that separates civilized man from the cruel and savage justice of the lynch mob, blood feud, or honor killing. As Aristotle notes in the Politics, it is the rule of law that separates that which is most divine in man from the beast: “One who asks law to rule, therefore, is held to be asking god and intellect alone to rule, while one who asks man adds the beast. Desire is a thing of this sort; and spiritedness perverts rulers and the best of men. Hence, law is intellect without appetite.”17 The divine character of law, that it is intellect freed from passion, also helps us to notice a moral dimension of punishment that we might otherwise overlook. It is because the penalties determined by law are impartial or dispassionate that they do more than simply deter future crime, or remove the future threat posed by the offender; they also manifest the transcendent order of divine justice, they show forth the moral order of God’s eternal law. As St. Paul says, the executioner’s sword is a minister of divine justice.18

Human law, then, is necessary for three reasons: 1) the wisdom and experience embodied in human law functions as a moral teacher for those who are well intentioned, communicating a more detailed knowledge of the natural moral law that is necessary for the perfection of virtue; 2) the discipline of law restrains and tames those who are passionate and unruly, moving them gradually toward virtue and keeping the peace; and 3) the rule of law enables public persons to exercise the virtue of restorative justice in a manner that is fair and impartial, thus manifesting the transcendent order of divine justice.

If Aquinas is right that the life of virtue can only be achieved by participating in the civitas, then the primacy of the political common good, at least insofar as it pertains to temporal happiness, should caution us against diminishing the importance of virtue as the ultimate end of political life. The deficiencies of our own political order, or any other political order, should not lead us to overlook the lofty character of the political common good, or to withdraw from the civitas in pursuit of a private happiness that will ultimately fail to satisfy our natural inclination to live in society with other men. The well-being of individuals and families depends on the existence of law and the larger more complete community of the civitas.



1. Summa Theologiae I-II, q. 98, a. 6.
2. Ibid., q. 101, a. 3.
3. Coercive power is not included in the very definition of law, but is a kind of per se property belonging to the person with the authority to make law. See Summa Theologiae I-II, q. 90, a. 3, ad 2; q. 92, a. 2; and q. 96, a. 5.
4. “It is natural for man, more than for any other animal, to be a social and political animal, living in a multitude….other animals are able to discern, by inborn skill, what is useful and what is injurious, even as the sheep naturally discerns that the wolf is an enemy. Some animals also recognize by natural skill certain medicinal herbs and other things necessary for their life. Man, however, has a natural knowledge of those things which are necessary for his life only in a general way, inasmuch as he is able to attain knowledge of the particular things necessary for human life by reasoning from universal principles. But it is not possible for one man to arrive at a knowledge of all these things by his own individual reason. It is therefore necessary for man to live in a multitude so that one man may be helped by another, and different men may be occupied by their reason with discovering different things, for example, one in medicine, another in this, and another in that.” On Kingship I.1.
5. See Summa Theologiae I-II, q. 95, a. 2.
6. “Now it is manifest that in him who has to govern not only himself but also the perfect community of a city or kingdom there is found a special and perfect kind of governance; because a government is more perfect to the degree that it is more universal, extends to more matters, and attains a higher end. Therefore prudence according to a special and most perfect sense belongs to a king to whom it belongs to govern a city or kingdom. And because of this a species of prudence is deemed regnative.” Summa Theologiae II-II, q. 50, a. 1.
7. Summa Theologiae I-II, q. 100, a. 1.
8. Ibid.
9. Ibid. For Aquinas, Moses is the paradigmatic example of the wise human legislator.
10. Ibid., q. 100, a. 3.
11. Ibid., q. 91, a. 2.
12. See Summa Theologiae I, q. 96, a. 4. One might object that the kind of rule that Aquinas envisions in an earthly paradise is not specifically political in its nature. It is not clear, however, why the rule of the wise would not consist principally in framing laws since law is essentially a work of reason and only secondarily and derivatively an exercise of coercive power.
13. Summa Theologiae I-II, q. 95, a.1.
14. On the need for law to regulate concupiscible appetite, see Ethic. X, lect. 14, n. 13. On the need for law to restrain irascible appetite, see Ethic. I, lect. 1, n. 4; and Summa Theologiae I-II, q. 105, a. 4, ad 5.
15. Summa Theologiae I-II, q. 96, a. 2.
16. Ibid., q. 95, a. 1, ad 2.
17. Politics I.16, 1278a28–31, translated by Carnes Lord, The Politics (University of Chicago, 1984).
18. See Romans 13:1–4.