Rev. Patrick Carter, O.S.B. (’05): “The Noble Due: Aquinas and Debitum Morale”

 

Rev. Patrick Carter, OSB, S.TH.D.
Secretary of the Curia of the Benedictine Confederation
St. Vincent de Paul Lecture & Concert Series
November 21, 2025
Video | Audio

 

0. Introduction

In this lecture, I am going to be examining the idea of debitum morale as used in the works of Aquinas. This is often translated as “moral due”. But given the broad possibilities of what the word “moral” and the word “due” might mean, I will often use the Latin phrase debitum morale. Our goal here is to understand better the meaning of the term and how it fits into the moral outlook of Thomas Aquinas.

I will begin by looking what I consider to be the most important text regarding this idea of debitum morale, question 80 of the Second Part of the Second Part. After that, we will look back at the passage of Aristotle that Aquinas points to as his source for this idea. There will follow a further presentation of a few more passages where the idea of debitum morale is used in various contexts. Then we will show how he uses the notion of debitum morale in analyzing a particular virtue.

There are several objectives that I would like to give to you before I start, in case you are wondering why this topic matters or of what interest it is. These should help assist you in following the whole of this lecture. The first is that this idea is one that Thomas Aquinas makes his own, in an innovative way. Second, he does this in the context of a desire for systematization of the virtues, grouped around the cardinal virtues. Third, the nature of the moral due is something that makes it quite noble and above the type of due involved in the virtue of justice.

0.1 The primary text: II-II, question 80, art. unic.

To begin, I propose to look first at what I consider the most important text where debitum morale is employed in the Summa Theologiae. This text is found in the Second part of the Second part, the Secunda Secundae, in the section where Aquinas is considering a division of the various virtues related to justice with the title: “Of the Potential Parts of Justice.” This Question 80 of the Secunda Secundae is one of the very few in the Summa that consist in only one article^[1], and the article itself is given the further specification: “Whether the virtues annexed to justice are suitably enumerated (assignentur)?”

Aquinas and the Scholastics in general had inherited a collection of lists of virtues, especially from Cicero, Macrobius, and Aristotle. These lists contained different kinds of elements that could not always be categorized as species or types of the virtue to which they were related. It was necessary, therefore, to provide an explanation of how they related to the cardinal virtue, and Aquinas dedicates a question to address all the parts in his treatment of prudence, fortitude, and temperance (qq. 48, 128, 143, respectively). For justice, one the other hand, he only dedicates a general question to consider the division among the potential parts.

The body of the article^[2] begins by providing a generic meaning of what makes a potential part of one of the cardinal virtues:

Two points must be observed about the virtues annexed to a principal virtue. The first is that these virtues have something in common with the principal virtue; and the second is that in some respect they fall short of the perfection (perfecta ratione) of that virtue.^[3]

The potential part, then, having something in common with the principal virtue of which it is a part, does not fulfill the perfect notion of the principal virtue.^[4] He then moves to apply this general principle to justice:

Accordingly since justice is of one man to another as stated above (q58a2), all the virtues that are directed to another person may by reason of this common aspect be annexed to justice. Now the essential character of justice consists in rendering to another his due (reddatur quod ei debetur) according to equality, as stated above (q58a11). Wherefore in two ways may a virtue directed to another person fall short of the perfection (perfecta ratione) of justice: first, by falling short of the aspect of equality; secondly, by falling short of the aspect of due (debitum).[5]

The nature of justice is that it governs our actions as related to others; it is ad alterum. This is the common note that the virtues annexed to it will all have. But justice has two marks or characteristics that will distinguish it from its potential parts. It renders to the other according to two aspects: the first is that something is owed and the second is that it must be rendered according to some kind of equality.^[6] The virtues that fall away from justice will be divided as to whether they fail in the aspect of equality or in terms of something being due.

It should be noted at this point that the falling short is said to be from the perfect notion (perfecta ratione) of justice, not from the perfection of justice itself, as some of the English translations state. It is deficiency from the definition of justice, not necessarily an inferiority or deficiency as regards to justice as something more perfect [Aquinas should be read in Latin]. The remainder of this first part of the body speaks of the first set of these virtues which fall short of attaining equality as is proper to justice. These include the virtues of religion, piety, and observance.^[7] [explain]

We pass on to the second set of potential parts which fall short of the side of the due, or debitum. Regarding this second set, he first lays out a distinction of debitum that allows them to be like the principal virtue, but manifests how they fall away from it:

A falling short of the just due may be considered in respect of a twofold due, moral or legal: wherefore the Philosopher (Ethic. viii, 13) assigns a corresponding twofold just. The legal due is that which one is bound to render by reason of a legal obligation (debitum legale); and this due is chiefly the concern of justice, which is the principal virtue. On the other hand, the moral due (debitum morale) is that to which one is bound in respect of the rectitude of virtue (ex honestate virtutis)...[8]

The potential parts of justice, like justice itself, govern our actions with respect to some debitum. In the case of the principal virtue of justice, this is a legal due. But this set of potential parts governs our actions with respect to a different kind of due, namely a one that he calls “moral”. This moral debitum is due from a certain nobility or integrity of virtue (ex honestate virtutis). [comment on bad translation] He refers to Aristotle’s Nichomachean Ethics, Book 8, as the source of this distinction between the legal and moral due, which we will examine in a moment.

Aquinas continues to develop the application of the moral due by distinguishing it into two degrees and applying that distinction to different sets potential parts:

...and since a due implies necessity, this kind of due has two degrees. For one due is so necessary that without it moral rectitude (honestas morum) cannot be ensured: and this has more of the character of due. Moreover this due may be considered from the point of view of the debtor, and in this way it pertains to this kind of due that a man represent himself to others just as he is, both in word and deed. Wherefore to justice is annexed "truth," whereby, as Tully says (De invent. ii, 53), present, past and future things are told without perversion. It may also be considered from the point of view of the person to whom it is due, by comparing the reward he receives with what he has done—sometimes in good things; and then annexed to justice we have “gratitude” which “consists in recollecting the friendship and kindliness shown by others, and in desiring to pay them back,” as Tully states (De invent. ii, 53)—and sometimes in evil things, and then to justice is annexed “revenge,” whereby, as Tully states (De invent. ii, 53), “we resist force, injury or anything obscure by taking vengeance or by self-defense.”[9]

The first set of virtues that attend to a moral due still imply a necessity that is essential for the preservation of good morals. Because of this necessity, these have more of the notion of debitum or due. This type of necessity can pertain to the person who owes it or to the person to whom it is owed. The former will be the case for the virtue of veritas, which is often translated simply as truth. The virtue of truth guarantees that someone represents himself and what he knows as he really is, implying a due proportion between words and thoughts. But other virtues will be based on goods or evils owed to the other, whether by the virtue of gratitude or by that of vengeance. Gratitude is mindful of friendship or the good services of others and takes care to recompense by means of thanks; vengeance defends against or avenges evil done to us.

The passage continues and proposes the other set of potential parts that attend to a moral debitum but in a distinct manner:

There is another due that is necessary in the sense that it conduces to greater rectitude (honestatem), although without it rectitude (honestas) may be ensured. This due is the concern of "liberality," "affability" or "friendship," or the like, all of which Tully omits in the aforesaid enumeration because there is little of the nature of anything due in them.[10]

These are not proposed as necessary for the preservation of moral integrity, but as rendering it greater in some way. He lists liberality, affability or friendliness, and other similar virtues. We will come back to this friendliness at the end.

0.2 Summary

So, let’s summarize briefly: Aquinas in this passage of question 80 of the Secunda Secundae employs the idea of different types of due / debitum to distinguish a set of virtues from the perfect notion of the virtue of justice. He states that the debitum morale arises “ex honestatis virtutis”, from the integrity or nobility of virtue. Then he makes a distinction from where this moral due is necessary for the preservation of virtue or where it contributes to a greater integrity (honestas).

In proposing this distinction between two types of debitum, Aquinas refers to the VIII book of the Aristotle’s Nicomachean Ethics. As we move into the consideration of this text of Aristotle, I believe that the historical context of the Nichomachean Ethics in the life of Aquinas, not very well known, sheds valuable insight.

1. Aristotle’s Idea

1.0 Arrival of the Nichomachean Ethics at Paris

In the first half of the 13^th century scholars had access only to the first three books of the Nicomachean Ethics.  These books were found in two works known as the Ethica Vetus (Books II-III) and Ethica Nova (Book I and fragments of others).^[11] The authors who wrote commentaries or who made use of these first books seemed to express awareness of the existence of the other books but declare that they did not have access to them.^[12]

The commentaries produced in the first part of the 13^th century were known to Albert and Thomas.^[13] Such commentaries had begun to raise the difficult issues related to the assimilation of the teachings of Aristotle into Christian moral theology.^[14] These works tended to take a very theological approach to interpreting the Nichomachean Ethics, and thus were at pains to come to terms with Aristotle’s philosophical consideration of the final ends of man and with his explanation of human virtue outside of the context of the Gospel.^[15]

But in the 1240’s, a master of Oxford and bishop of Lincoln, Robert Grosseteste, produced a complete translation of the EN from the Greek original.^[16] This translation would have arrived at Paris towards the end of Albert’s time there, most likely in 1246 or 1247. The work was translated and published along with translations of some Greek commentaries and also included textual annotations of Grosseteste himself. These editorial notes often were of a philological nature and offered explanations of various Greek words or their translations into Latin.

1.0.1 Albert and Thomas in Cologne

Albert immediately got to work with this new text in Paris before being sent to found a new studium in his native land, at Cologne. As we know, he took the bright young Thomas along with him. There Albert made commentaries on the works of Dionysius and on this new work of Aristotle, now available in its fullness. We have the proof of their collaboration in a manuscript of Dionysius from the 11^th century, which has been determined to have additional readings collated from another manuscript, in the very hand of Thomas Aquinas. He was serving in some capacity as the research assistant of Albert and would have assisted in compiling the very first full Medieval commentary on the newly available EN.

Albert’s first commentary (there was a second one much later) is thorough and complete. He carefully analyzes the text of Aristotle in a lengthier and more complete way than Aquinas himself would do later in his own career.[17] Thus at the very beginning of his formation, Aquinas had a chance to make a thorough study of the newly available text of the Nicomachean Ethics, and to work with Albert on making his commentary. This period in Cologne with Albert (1248-1252) predates any of extant works of Aquinas, and we will see further on in this presentation that Aquinas wasted no time in employing the idea that he found in Aristotle.

1.0.2 Albert’s Contribution

Albert’s career spanned a period before and after he had access to the most important parts of Aristotle’s EN. In Albert’s early works, the notion of debitum plays a prominent role and defines the very nature of the virtue of justice. In his first contact with the complete text of the EN through the translation of Grosseteste, Albert remains very close to the text of Aristotle himself and does not often make use of the word debitum. Nonetheless, in his later works, Albert returns to this language in which the rendering of a debitum defines the proper act of justice.

One can see that there must have been a strong tendency in the schools to define justice in this way. Albert himself often equates debitum with ius or uses it to specify the debitum proper to the special virtue of justice. This would indicate that one of the influences of Albert on his disciple Thomas that should be sought, whether in Paris, Cologne, or Orvieto, is this tendency to identify the object of justice with debitum.

At the same time, Albert did not make use of this idea when discussing the text of the Nicomachean Ethics which we are about to look at. We could say that he does not put any emphasis on the distinction that Aquinas cites from the passage: he analyzes the passage and moves on. So Albert’s contribution is more in conceiving justice as a rendering of a debitum, rather than on the particular use of the idea taken from Aristotle.

1.1 EN VIII, chapter 13

We finally arrive at the eighth book of Aristotle’s Nicomachean Ethics. It is dedicated to an analysis and division of friendship. The passage Aquinas refers to, in most English editions, is found in chapter 13 of this book where Aristotle is considering the friendship of utility.

Let’s go straight to the text itself, where Aristotle is distinguishing two kinds of friendship of utility:

It seems that, just as there are two kinds of things which are just, one unwritten and the other according to law, so there are two kinds of friendship based on usefulness, one ethical (ἠθικὴ) and the other legal (νομικὴ). Accordingly, accusations arise especially whenever exchanges are made not according to the same kind of friendship and the parties break off their friendship.[18]

First it should be noted that there appears to be a reference to a passage about justice in Book V of the EN.^[19] Unfortunately there is not time here to examine this other passage and its parallel with the distinction here. Aristotle proposes that the cause of accusations which lead to the end of friendships of utility is a lack of mutual understanding about the nature of the agreement in a friendship of utility. He makes an initial distinction between the ethical (ἠθικὴ) and the legal (νομικὴ).

Let’s allow Aristotle to explain the terms: first, the legal type:

Now legal friendship is formed on specified terms; and it may be purely commercial and carried out immediately, or it may be more liberal with respect to time but agreed upon as to its terms. The debt in the latter case is clear and not subject to dispute, and the postponement has an element of friendship; and it is in view of this that some states allow no suits concerning those debts but think that men should accept the consequences regarding exchanges based on trust.[20]

Legal friendship is founded on a specific agreement: ἐπὶ ῥητοῖς. This phrase of Attic Greek does not simply mean ‘upon something stated’, as ῥητός can mean by itself. Rather, that which is ‘stated’ is understood to be terms of an agreement.^[21] There is an understanding between the two parties about how the exchange is going to unfold. Such agreements can be immediate, or ‘from hand to hand’, as the Greek has it. Debts can also be ‘more free’ in the sense of providing a period of time before the debt needs to be paid. The very fact of this flexibility of time to repay a debt is a sign of trust and friendship. Aristotle comments that these more flexible forms of exchange sometimes preclude opening a suit against the debtor, and the same will apply all the more in ethical friendship, which he addresses next:

Ethical friendship, on the other hand, is not formed on specified terms; a gift or any other good is bestowed as to a friend. But the giver expects to receive as much, or more, as if what he gave were not a gift but something lent to be used; and if at the end of the exchange he is not as well off, he accuses the receiver.[22]

Obviously when the precise nature of the exchange is not based on any agreed terms, the situation can generate conflict. Someone gives something or does a service for another as for a friend. But he expects repayment and will fall to accusation if the other does not recompense him for the favor. Sometimes the motive seems to be generosity and thus indicates that the giving is in a gratuitous manner. But then the reality of the giver’s intentions is made clear when he later expects some return and is offended when he is not recompensed. Aristotle next explains the reason why this happens:

This happens because all or most people, though wishing what is noble (καλά) deliberately choose what is beneficial to themselves. Now to treat others well without seeking a return is noble, but to receive the services of another is beneficial.[23]

There is a discrepancy between the way that people want to be perceived as acting, and the way that they wish others to act. Often, one wants to appear generous and liberal, while at the same time desiring a due return on their own generosity. Sometimes exchanges have an uncertain character simply due to the improvised manner in which they play out. Often circumstances can place us within such exchanges regardless of our virtue or intentions. In the moment one might intend to act with generosity, but then one later prefers to receive something for the benefit conferred. While it is unlikely that this change will occur on the part of the virtuous man, he could still be the recipient of generosity at the hand of a friendly acquaintance.  Given these discrepancies found in human behavior, Aristotle proposes some guidelines for how the virtuous man should act in these situations:

So if the receiver is able, he should return the equivalent of what he received and do so voluntarily; for no one should be made an unwilling friend. It would really be as if one made a mistake at the start and received a good from a person from whom he should not have received it; for he received the good not from a friend, nor from one whose action was for its own sake. Accordingly, he who has so received a service should dissolve the friendship as if it were made on specified terms. And he should grant that, if he could, he would return the equivalent of the service rendered, for if he could not, neither would the giver have expected to receive it; so if he can, he should return the service. But a man should first consider carefully (a) the person from whom he receives a service and (b) the terms on which he does this, so that with both these in mind he may accept or decline it.[24]

The advice of the Philosopher is that one should try to voluntarily repay debts based on these uncertain forms of ethical friendship as if they were agreements made with fixed terms as in the case of the legal friendship of utility. This avoids the conflict where one might presume that the thing was given gratuitously as if from a friend and thus try to make a friend out of a person that was intending to act for the sake of exchange. In the case where someone gives something that he knows cannot be repaid, then return cannot be expected from him. Finally, one should consider who is rendering us a service and on what terms it is being rendered to decide as to whether to receive the service or not, as in some cases, a recompense might rather give offence.

1.2  Implications: friendship and justice

It should be noted that Aristotle’s solution for the problem of ethical friendships of utility is that the recipient should be ready to pay the other back as if it were a legal friendship of utility or a simple transaction of justice, if in fact he can do so. The passage gives the impression that both types of friendships of utility relate closely to commutative justice.  Does anything distinguish the friendship of utility from a simple relationship of justice?  Is it in fact necessary in these friendships that there be some further element which makes it a friendship rather than just a transaction of justice?

These questions are quite pertinent to the above passage that we have examined; Aristotle himself admits that friendship and justice have the same matter and involve the same persons:

...both friendship and what is just seem to be concerned with the same things and to belong to the same persons; for in every association there seems to be both something which is just and also a friendship. At least, men address their fellow-voyagers and fellow-soldiers as friends also, and similarly with those in any of the other associations. Friendship goes as far as the members associate with each other; for what is just extends as far also…. What is just, too, increases by nature along with friendship, since they depend on the same kind of things and extend equally to them.^[25]

Whatever be the differences between justice and friendships, they come into play regarding the same things and the same persons. Whenever men interact in various human societies, there is always the possibility of friendship and justice to enter to govern their association.

With respect to the matter, friendship of utility has as its basis commercial exchange or services and thus has a matter that is closely related to commutative justice. Considering the equality implied in these friendships, when there is doubt as in the case of certain exchanges of moral friendship of utility, Aristotle’s recommendation is to act as if the person was not a friend and to render in return what is just for the favor or goods received. Part of the danger of these types of friendship is precisely the question of clarity of merit or debt. In both legal and moral friendship of utility, the necessary basis of the friendship is equality through exchange.

While it can be claimed that all types of friendship involve goodwill (εὔνοια) for the friend, there is certainly a hierarchy in the types of friendship. Friendship of virtue^[26] is better because its matter, the good character of friends, is more stable and less apt to change and to lead to the destruction of the friendship. The other types generate their rapport and goodwill from less stable matter, pleasure and utility, which can easily pass and lead to the dissolution of the friendship. In the equality of friends of virtue, a quantitative likeness is more important between the friends. But in that of the friendship of utility, there is real need to maintain an equality of merit or debt, and this is shown by the virtuous approach to situations of confusion when one should act by the demands of justice and not presume on the other’s part a generosity proper to friendship.

It can be seen, therefore, that Aristotle views his treatment of friendship as natural continuation and development of his treatise on justice in Book V.^[27] This is because, as he states, justice and friendship relate to the same persons and the same matter, while having a different way of demanding equality. Friendship perfects the relationships of “pure” justice that one finds in political and social contexts. Hence, “… when men are friends, they have no need of justice at all, but when they are just, they still need friendship; and a thing which is most just is thought to be done in a friendly way.”^[28] Obviously friendship does not dissolve the demands of justice but guarantees that they are fulfilled spontaneously.

This difference in the mode of equality, however, is less important in friendship of utility. The progress of virtue and of friendship make justice unnecessary insofar as the friend acts beyond the simple demands of justice. There is an inverted relationship in which the need for justice decreases as the presence and quality of friendship increases.^[29] The friendship of utility is found in an area where the need for justice is still quite prevalent. It requires the maintenance of a proportional equality between the two friends in the context of their exchanges. This places it very near justice and when confusions arise about the type of exchange involved in the moral friendship of utility, the result is the need to retreat to just action and rendering what is due according to strict justice. Here justice is seen as a sort of fallback mechanism when these friendships of the lowest type fall short, as they are often wont to do (given human nature in its fallen state).

[the Eudemian Ethics – parallel passage, more condemnatory]

1.5 Conclusion on Aristotle

Aristotle proposes within his treatise on friendship a distinction between two types of friendship of utility. This distinction, seen in parallel with two types of just action, includes a moral and a legal type. The moral type is one where the parameters of the exchange are not determined explicitly, and the retribution is left in the hands of the recipient of the goods or benefit. The legal type, on the other hand, is based on an explicit agreement which may or may not allow for some flexibility.           

These two types are introduced in the discussion of conflict within friendship. Aristotle describes how the lack of a clear agreement between the parties in the moral type is a cause for strife to arise within this type of friendship. This is due to the tendency to fall into self-interest and not give what one ought to the other. This tendency is not checked by clarity in the exchange, and one is tempted to take the opportunity of the lack of agreement in the friendship to not render what is owed due to the general tendency to act in self-interest.

This deficiency is the result of the moral type being fundamentally flawed as a friendship of utility. The moral friendship of utility leaves the determination of the return for services or favors in the hands of the other party: it is unwritten and undetermined rather than written or explicit. This causes problems because the other party may or may not decide to render a due return. Such an agreement leaves the estimation of what is owed to the judgement of the partner in the friendship of utility. This subjective sense of what is owed is, however, proper to the friendship of virtue, the highest kind of friendship, and not to friendship of utility, the lowest type.

This the tendency for arguments arising in this lowest form of friendship manifests the connection between friendship and justice. At the limit of these friendships of utility, the friendship’s existence relies on the strict preservation of justice, which is endangered in the moral type of friendship of utility. But the exalted nature of the moral type is only problematic because it is misplaced in the friendship of utility; it belongs rather in the highest type of friendship that of virtue or excellence, where friends render service to one another freely and generously, fulfilling what is just and more without any need for contracts or agreements. The moral type, therefore, includes something inherently praiseworthy which is misplaced when situated in a context of utility.

2. Aquinas throughout his Career

What I would like to do know is to examine several places where Aquinas uses the idea of debitum morale throughout his career, without any attempt at being exhaustive, in order to illustrate the way that he applies and conceives this notion across his works.

 

2.1 Scriptum Super Sent. III, d. 33 q. 3 a. 4 qc. 1 co[30]

The first passage comes from the Scriptum Super Sententias (often called the commentary on the Sentences). This was St. Thomas’s first written work, and it was undertaken almost immediately after his period in Cologne with St. Albert: he made no delay in employing this idea that he had picked up from the EN, even though Albert himself had not given it much attention.

The third book of the Sentences of Peter Lombard treats of the Incarnation of the Word. The book begins with a thorough consideration of the mode of the Incarnation and of various aspects of the life of Christ which constitutes about half of the book. There follows a discussion with more general considerations about the theological and moral virtues. In this part, after having considered the moral virtues in general and then particularly (d. 33 q. 1-2), the text examines the parts of the moral virtues. The parts of justice are treated last in article four.[31]

In the determination of the first questiuncula, Aquinas first takes the opportunity to show how justice differs from temperance and fortitude in that it deals with external acts that must be moderated or measured in relation to the other rather than in relation with the agent’s own passions.[32] He gives the example of adultery, which is both an offence against temperance, due to the unmanaged passions that it implies, but also against justice, in that it involves the use of something that rightfully pertains to another. Justice is characterized by this orientation outside of oneself.

He then uses the principle of ‘adaequatio’, an equaling or leveling, in order to describe justice in which one must make equal by rendering what is due (debeo, debitum). The different parts of justice will be determined by how they preserve this mode of moderating or rectifying our actions in relation to the other person. The subjective parts of virtue, which will be species of justice on par with the special virtue, preserve this mode of moderation. There are other virtues which do not contain all the aspects of this moderation; these will be the potential parts of the virtues.

The he continues to describe the characteristics of justice along with the ways in which the potential parts of justice can fall short, in a way similar to the passage in II-IIq80 that I spoke of at the beginning. Religion and piety, for instance, fall away from the full nature of justice because they cannot reach equality between us and God or our parents, because we cannot render enough to attain equality. But despite being incapable of reaching this equality, such virtues still render something from the obligation of law, “ex obligatione legis”.

Then he arrives at the other set of potential parts that interest us here which do not have this legal obligation:

There are also some by which one renders to another what he owes him not by the necessity of the law, but by a certain integrity (quadam honestate), as the Philosopher says in the Ethics 8; for example, gratitude, which is a reciprocation for benefits received, according to Cicero, and also mercy and the like. And these virtues are a little bit more distant from true justice.[33]

Here he distinguishes between a rendering according to the necessity of law and that according to ‘quadam honestate’, a certain integrity or nobility. He associates here with this integrity the virtues of gratitude and honesty, as he also does in the Summa Theologiae.

From the very first time Aquinas undertakes his own division of the virtues, he pointed to this legal/moral distinction from the Nicomachean Ethics. It is now put to work in a much different context than that in which Aristotle had employed it, but it does not fundamentally change. It is clear that the due of gratitude is not something that one can exact from someone, though it is truly owed, but that must be rendered freely by the recipient of some favor. In gratitude, there is no contract, implied or explicit, which is violated by failure. Yet, anyone who is raised well recognizes that thanks is a sort of duty, one that makes a person virtuous.

Aquinas uses this idea again during this first period of his career. in his Contra Impugnantes, Q. 7. Questiuncula 3 ad 4 (Part. 2 Cap. 6 ad 27). Without going into the text, he there refers the support that mendicants receive from preaching—responding to William of Saint-Amour who had claimed that mendicants should not receive salaries—as coming from a friendly justice as a opposed to a legal one, referencing the distinction coming from EN VIII. The recompense given to a preacher for his work preaching he distinguishes from the purely gratis gift that is given to a pauper, where there is no basis of due on the part of the other.

2.2 Sententia libri Ethicorum, lib. VIII lectio 13

Aquinas’s commentary does not go into great depth on the distinction; he largely paraphases the text of Aristotle. But let us look at the precise section and see what he says about this debitum morale in the passage from where he has drawn the distinction:

Likewise, utility properly acquired in friendships is of two kinds. One is moral, according as a person provides another with help in conformity with moral practice (ad bonos mores); and this utility answers to what is just, but not written down. The other is legal utility, according as a person provides another with help in conformity with a statute of law. Now complaints arise in useful friendships especially when an exchange of utility is not made according to the same standard. One bestows help according to the requirements of law, but the other demands it according to moral practice (convenientiam bonorum morum). And in this way friendship is broken up.[34]

And he continues further on about the moral type:

At moral utility, however (1162b31), he explains what moral utility is. He says it is not expressed in definite words or compacts made by agreement, but without any contract externally declared, a person gives to someone else what is usually given freely to a friend. However, the man who makes a worthy gift intends and expects in return something equal or even better, as if he were not making a gift, but a loan. But when an exchange does not take place in such a way that the recipient restores and pays equal or more, the giver will accuse the recipient and complain of him.[35]

We should note here that Aquinas is mostly summarizing the text of Aristotle. But in these texts two things should be noted. The first is that he uses the phrase good character (bonos mores) twice: the moral type pertains to this integrity of character. Second, that the moral type is similar to the way in which one gives to a friend: freely and without expectation of a reciprocal return. This aspect is the reason that such a type, while inappropriate here in the friendship of utility, can be the basis for virtues connected with justice.

Here should be added a brief point about the idea of good character, or boni mores. Boni mores is sometimes used in a way that appears to equate it with honestas. At the same time, recalling the passage from ST I-II q100 a1 co. where Aquinas is considering the Old Law, the phrase can pertain to the whole of virtue. The teaching of this article[36] indicates that some of the realm of moral action must be determined by reason in its specifics, even if the whole of virtue is indicated by natural law in a generic way. Boni mores, I believe, indicates the traditional and formative aspect of the cultural reception of these further determinations, as is implicit in the meaning of mos. These determinations come not from just any moral subject, but from our wise elders who hand on what they have received rightly.

2.3. II-II q23 a3 ad 1

Moving back into the Summa Theologiae, there is a passage previous to the treatise on justice where Aquinas uses this distinction. Question 23a3 responds to the question of whether charity, as friendship, is a virtue. And he responds to the first objection that Aristotle did not consider friendship to be a virtue:

The Philosopher in Ethic. viii does not deny that friendship is a virtue, but affirms that it is either a virtue or with a virtue. For we might say that it is a moral virtue about works done in respect of another person, but under a different aspect from justice. For justice is about works done in respect of another person, under the aspect of the legal due (sub ratione debiti legalis), whereas friendship considers the aspect of a friendly and moral duty (sub ratione cuiusdam debiti amicabilis et moralis), or rather that of a gratuitous favor, as the Philosopher explains (Ethic. viii, 13).[37]

We should be careful here not to confuse what he says about friendship and charity with that which he will say about the virtue of affability. The obligation that charity implies is appropriate to friendship in the fullest sense. In the context of friendship of utility, it is out of place, but takes on its full role in the context of the noble friendship, especially that of charity.

 Here Aquinas directly connects the notion of friendship with debitum morale. Justice renders to the other under the idea of a debitum legale, a legal or binding due, whereas friendship renders under a moral or friendly due. Indeed, I believe that this phrase “a friendly and moral duty” is a hendiadys: he is expressing the same thing with two words, and shows us that he sees the nature of the moral due as essentially the kind of duty that one finds in its completeness in friendship.

2.4 Conclusion from the preceding texts

Aquinas as a young teaching assistant came across the idea of two types of friendship of utility in Aristotle’s Nicomachean Ethics. Although we could not study the texts of St Albert the Great, it is clear that he does not use the idea to the extent that Aquinas does, if at all. It is Aquinas’s innovation. He further applies it to the idea of due, debitum, something not found in the text of Aristotle, or which is at least only implicit.

His use reveals certain aspects of this moral due which follow from the distinction of Aristotle. This type of due is based on a certain integrity, which is denoted with the terms honestas and boni mores. It is something proper to friendship of a higher kind and not appropriate in the friendship of utility, where it leads to conflicts.

Further, the due that is moral is not always optional: in some contexts, it is necessary for the preservation of good morals, in other contexts, it is conducive or indicative of the greater preservation of virtue. It falls short of the notion of the cardinal virtue of justice, but in not so as to be inferior to it. It relies more on the good moral character of the person acting than on the external requirements demanded by a legal due, while still pertaining to another.

3. Amicitia: II-II q114 a2 co., ad 1

To be a bit more concrete, I would like to briefly examine one of the several places where Aquinas uses the idea of debitum morale to treat with a particular virtue. The virtue I will examine, in Latin, is called amicitia. We are not talking here about friendship in the sense of Aristotle or as Aquinas considers charity, but rather something that is frequently translated as affability or which we could call friendliness. This virtue is presented in question 114 of the Secunda Secundae.

Amicitia, discussed in Secunda Secundae q114a1, is a virtue which renders our exterior actions towards others in society fitting and decent. It is the fruit of a general attitude of friendship towards all those with whom we live in society.  It leads us to be pleasant towards those around us unless some good and necessary motive causes us to sadden them.

In the second article of the question, the relationship of the virtue of affability with justice is considered. In his response, Aquinas applies the notion of moral debt to tie affability to the principal virtue of justice:

This virtue is a part of justice, being annexed to it as to a principal virtue. Because in common with justice it is directed to another person, even as justice is: yet it falls short of the notion of justice, because it lacks the full aspect of debt, whereby one man is bound to another, either by legal debt, which the law binds him to pay, or by some debt arising out of a favor received. For it regards merely a certain debt of equity, namely, that we behave pleasantly to those among whom we dwell, unless at times, for some reason, it be necessary to displease them for some good purpose.[38]

There is not a full sense of due in the matter of this virtue. Living pleasantly with others involves a certain equity by which we make life pleasant for the others in our society. This virtue would include things like greeting someone with “Good morning”, taking care of personal hygiene, removing a hat when entering a building (this applies principally to men), being considerate when walking, and many other things too numerous to name. (Of course, the right measure of such things is going to vary from culture to culture.) At the same time, there are moments when it might be necessary to displease others. If there is some emergency, such as a fire, it would be inappropriate to stop first to brush your teeth in order to not annoy your neighbors when you start shouting “Fire” in the hallway.

But this is a real virtue, and a sign of moral perfection when one is able, especially in challenging social situations, to maintain respect and consideration for others. It requires an interior sense that we should not inordinately displease the other when it can be avoided.

In this article, the first objection had rejected the idea that affability or friendliness could pertain to justice because it lacks any sense of debitum and merely attempts to please those around us. In responding, Aquinas shows how the social aspect of human nature can create certain debts towards those with whom we live:

As we have said above (Q. 109, A. 3, ad 1), because man is a social animal he owes his fellow-man, in equity, the manifestation of truth without which human society could not last. Now as man could not live in society without truth, so likewise, not without joy, because, as the Philosopher says (Ethic. viii), no one could abide a day with the sad nor with the joyless. Therefore, a certain natural equity obliges a man to live agreeably with his fellow-men; unless some reason should oblige him to sadden them for their good.[39]

A parallel is proposed between the need for telling the truth and the need to please those around us. If no one told the truth, it would make life in common very difficult. Likewise, if everyone were brusque and unfriendly, it would be very hard to sustain life together with others. His conclusion summarizes his teaching on this virtue: “A man is held by a natural duty of good manners (honestas) to live with others so as to be pleasing, unless for a particular cause it is necessary to sometimes sadden others.” Here it can be seen that the social nature of man is the basis for this moral duty of truth and affability. It is a due, but not a legal one, rather one that ennobles the virtuous man by showing consideration for those around him.

 

4. Conclusion

The notion of debitum morale is broad and is applied in different contexts which render its meanings analogous. It is a relation that arises within the moral subject toward the object of virtuous action as distinct from legal, objective debts like that which pertains to the special virtue of justice. It tends towards friendship, both in definition and in fact. Its measure is the noble or beautiful good which can be extended to the whole of virtue. For apprehending well this limit, one needs the assistance of cultural wisdom handed down in custom and of the guidance of the morally wise. The virtues which render this noble due are signs of greater virtue and a more virtuous man, as they transcend what is merely required by the cardinal virtue of justice and are signs of a nobility, honestas, of character. Thus we can rightly call it a duty of integrity, a moral debt, noble due.

I believe that if we actively seek to develop our own sense of this noble due, we will become better that if we merely aim at justice in regard to our fellows. Seeking to fulfill this noble due in truth, in affability, in gratitude, in liberality, makes life better for everyone around us, and it prepares and increases the possibility of friendship. It carries us to fulfill the demands of justice (without which it would be in vain to cultivate friendliness and other such virtues), and to go beyond in a way that moves us towards charity, the queen of the virtues.

 

Receive lectures and talks via podcast!