Differentiation: Where do Obligations Fit in the Roman View of the Law?

Let us start by assuming that �the Roman view of the law' is the view of the Institutes of Gaius and Justinian. Both use the same means of dividing the whole mass and thus bringing it under control.

Omne autem ius quo utimur vel ad personas pertinet vel ad res vel ad actiones. Et prius videamus de personis.

All the law we use has to do either with persons or with things or with actions. And first let us consider persons.

I have left in �And first let us consider persons' because it serves to reinforce the fact that this threefold division is indeed the basis on which Gaius intends to structure his exposition.

obligations belong in the law of things. They hold their place there by virtue of the division between things corporeal and things incor­poreal. This is Gaius at G.2.12-14. I give Zulueta's translation with some bits of Latin in brackets.

12. Further, things (res) are divided into corporeal and incorporeal.

13. Corporeal things are tangible things (quae tangi possunt), such as land, a slave, a garment, gold, silver, and countless other things. 14. Incorporeal are things that are intangible, such as exist merely in law (quae tangi non possunt, qualia sunt ea quae iure consistunt), for example an inheritance, a usufruct, obligations however contracted. It matters not that corporeal things are comprised in an inheritance, or that fruits gathered from land (subject to a usufruct) are corporeal, or that what is due under an obligation is commonly corporeal (et quod ex obligatione nobis debetur plerumque corporale est), for instance land, a slave, money; for the rights themselves, of inheritance, usufruct, and obligation, are incorporeal (nam ipsum ius successionis et ipsum ius utendi fruendi et ipsum ius obligationis incorporale est).

I have let this passage run on a bit because the job of fitting obligations in their place is not finished when one has said that they are in the law of things as �res incorporales’. It is also necessary to differentiate obliga­tions from these other incorporeal things.

Nevertheless we have got some way already. All the law is about persons or things or actions. Things divide between corporeal and incorporeal. Incorporeal things divide between those which are not and those which are obligations. That is quite an elegant bit of map­making. Is there any obvious problem with it? There is one. An obligation is prima facie a burden. As we saw, it looks, at least in English, from the duty end of the relationship, not from the right or benefit end. How can it line up with land, slaves, garments, gold, inheritances, usufructs and all these other good things? They are all items of wealth. They suggest that a good translation of res would be �asset’. But, according to the sense we want to give it, an obligation is not an asset. It belongs in the other column, a minus rather than a plus, a negative asset (if that is not nonsense).

There are two ways out of this difficulty. You either stick with the translation of res as �asset’ and adjust your view of the Roman under­standing of obligatio or, vice versa, you revise �asset’. This is not a small thing since it affects the whole way in which one sees the ius rerum, the second division of the tripartite institutional scheme. What adjustment is possible for the meaning of obligatio? To make the word sit happily in a list of �assets’, you have to change the angle of vision from the burden end to the benefit end of the rope. Or, at the very least, you have to make the word neutral as between the two points of view. Suppose you have received a mistaken payment from me. You are under an obligation to pay it back. To make the obligation an asset it must be possible for the words �my obligation’ to be used by me as well as by you. By me to denote my right against you that you should pay. For only if that usage is possible (obligatio = right, claim) is an obligation an item of wealth. What adjustment is possible to res? If it is not �asset’ or �item of wealth’, it must be just �thing’. �Thing’ is very vague but it can be firmed up a little in two ways. First, by opposition. Many legal terms only become clear when you look for their opposites; or, more accurately, for what they are meant to exclude. So here �thing’ acquires boundaries by opposition to persons on the one hand and actions on the other. Secondly, by a core case. Again, many legal terms depend for their intelligibility on their having, so to say in their centre, an example or some examples about which nobody would disagree that they are properly described by the word in question. So here res can take meaning from the core at its centre, undoubtedly the corporeal item of wealth (land, garment, gold ingot), without being required to be free of uncertainties and instabilities in its periphery. More accurately, without being required to have no periphery of less certain cases.

As between these two ways out of the difficulty i myself incline to the second. The other is the one generally adopted. The issue is genuinely uncertain. i have not myself seen any convincing example in which mea obligatio or obligatio with a genitive indicates right rather than duty.

Subject to this doubt, it remains true that obligations belong in the law of res as one species of res incorporalis. The next question is: how do obligations differ from the other incorporeal things? At this point it is very easy to slip into a not quite Roman form of explanation. And if we are going to do that, at least we ought not to do it without knowing what is happening.

The other res incorporales as Gaius gives them are inheritance (hereditas), usufruct and praedial servitudes (iura praediorum). He does not call usu­fruct a servitude but it came to be described as a personal servitude, and there were others in the same category, all in the nature of reduced or cut down usufructs. Just as praedial servitudes are, in Latin, rights of landholdings, so personal servitudes are rights of persons, iura personarum. The reason for setting out this terminology is that it provides the basis for asserting, as we shortly shall, that there is all the difference in the world between iura personarum and iura in personam (rights of persons and rights against persons). A right of a person may be in rem (against a thing). For the moment this will seem merely muddling. it had better not do later. For the difference between in rem and in personam is of fundamental import­ance. They are analytical tools which no lawyer can do without.

Take just one of these other incorporeal things.

By contrast, when the res is not Daisy or a usufruct but an obligation, the action always takes a form of words directed against a person. And the res which is the obligation itself is not mentioned at all. its existence is a matter of inference from the words which are used. What the plaintiff says, again in the simplified equivalent of the example in the last paragraph, is �You ought to convey Blackacre to me.’ And this comes out in the formula as �If it appears that the defendant ought to convey Blackacre to the plaintiff, for as much as Blackacre shall be worth condemn the defendant to the plaintiff; etc.’ The primary contention of the plaintiff is that the defendant ought to do something. The words are directed against that person. There is no such pleading as can be boiled down to this, �I say the obligation that you should...

The �defendant ought' actions (all based by inference on obligations) are directed against a person rather than a thing. They do not name the abstract thing which they seek to realise, the obligatio itself. Those two sentences are correct. But it is incorrect to go further and say that such actions do not name any res at all. They say what the defendant ought to do. And since the content of his obligation will often be the giving of, or some other doing to, a thing (whether corporeal or incorporeal), saying what he ought to do will often mean naming a thing. �You ought to convey Blackacre to me.' Blackacre is named. But the words of my claim hit you first and then bounce back on Blackacre. Contrast �Blackacre is mine'. Here the words dive straight down into Blackacre.

The question was, How would the Romans have seen the difference between usufruct and obligation? The answer has been that they would have said it was a matter of different patterns of action. Usufruct was claimed by an action in rem (a pleading immediately directed against the res); an obligation was enforced by an action in personam (a pleading immediately directed against a person).

At this point i want to underpin what has just been said by looking at the opening passage of Gaius's treatment of the third of his main divisions, namely actions. This is G.4.1-5. Again the translation is Zulueta's.

1. It remains to speak of actions. Now, to the question how many genera of actions there are the more correct answer appears to be that there are two, in rem and in personam. For those who have maintained that there are four, counting the genera of sponsiones (i.e. of actions per sponsionem?), have inad­vertently classed as genera certain species of actions. 2. An action in personam is one in which we proceed against someone who is under contractual or delictual obligation to us, an action, that is, in which we claim �that he ought to convey, do, or answer for' something (cum intendimus dare facere praestare oportere). 3. An action in rem is one in which we claim either that some corporeal thing is ours, or that we are entitled to some right, such as that of use or usufruct, of foot- or carriage-way, of aqueduct, of raising a building or of view. On the other hand an action (in rem) denying such rights is open to our opponent. 4. Having thus distinguished actions (sic itaque discretis actionibus) we see that we cannot sue another for a thing belonging to us using the form of claim �if it appears that the defendant ought to convey (dare)'. For what is ours cannot be conveyed (dari) to us, since obviously dari means the giving of a thing to us with the effect of making it ours [obviously? scilicet]; but a thing which is already ours cannot be made more so. It is true that out of hatred of thieves, in order to multiply the actions to which they are liable, it has become accepted that, in addition to the penalty of double or quadruple, they are also liable in an action for the recovery of the thing in the form: �if it appears they ought to convey’ [sipareteos dare oportere], notwithstanding that the action claiming ownership of the thing lies against them as well. 5. Actions in rem are called vindicationes; actions in personam, claiming that there is a duty to convey or do [darefierive oportere] are called condictiones^[11]

You can see from this passage, first that claims are divided between those which are framed against a thing (in rem) and those which are framed against a person (however they may also be about a thing) and, secondly, that the two types are kept contentually separate by the technical interpretation of dare. It is not nonsense to say, if you have my cow, that you �ought to give it to me’. But that common sense would allow the claim to express two fundamentally different ideas, �owning’ and �being owed’. The understanding of dare as �convey’ stops that happening. The case of thieves is the exception which proves the rule.

At this point we should regroup. The proposition was that obliga­tions hold their place in the institutional scheme by virtue of being �things’ and, in particular, �incorporeal things’. The immediately fore­going discussion has been about the difference between obligations and other incorporeal things, inheritance, usufruct and praedial servitudes. It has been exploring the question, How would Gaius himself have expressed that difference? One reason why that question is difficult is because we now express the difference in a way which itself (despite Latin labels) is not quite Roman. The next few paragraphs are intended to give the modern way of putting it.

We say that the difference turns on the nature of the right held by the plaintiff, and we do not talk in terms of forms of words used in making claims. The distinction is between rights in rem and rights in personam. And the distinction between obligations and the other incor­poreal things is then that (looking from the benefit end of the rope) obligations connote rights in personam and the others are rights in rem.

i. The difference between rights in rem and in personam

A right in rem is one which depends for its exigibility on the location of a thing. A right in personam is one which depends for its exigibility on the location of a person. �Exigibility’ means �ability to be demanded'. And when it comes to exacting rights of either kind there is always a person at the receiving end of the demand.

Consider rights in rem first. Ownership is the instantly recognisable example. Suppose that i own the cow Daisy. She somehow comes into the possession of another person. �Somehow’ means �by some series of events other than a transfer of my title’. Let us say that she just wanders off to your field or was driven there in the dead of night. So long as i do not know where she is i cannot effectively demand my right in her. it is true that i can go from place to place and person to person saying �Daisy is mine.’ But I cannot achieve very much by doing so. I cannot realise my right unless i find out where Daisy is. on the other hand when I do find out where she is her location determines the identity of the person from whom I can exact my right. Her possessor, even though I have never encountered him before and had no dealings with him, is the person against whom I can effectively assert �This cow is mine.’ It is sometimes said that a right in rem is one which can be enforced against the whole world. This is what that means, the location of the res determines the person from whom the right can be exacted. Until I know who has her I can do nothing; when I know who has her I know who must be confronted. Notice what happens when the cow ceases to exist. My ownership becomes a thing of the past: �I did own Daisy.’ It is nonsense to say �I own’ of something which has ceased to exist. The same of something which has not yet come into existence. This is all part of the statement that exigibility depends upon the location of the thing. You cannot locate a thing which does not exist.

Two points need special mention. First, the definition turns on exigibility, not on alienability. Usufruct is a right in rem. If I have a usufruct in the cow Daisy I can demand that right against anyone in possession of Daisy. Her location determines the identity of the defendant. But usufruct in Roman law was an inalienable right. If my father’s will made me usufructuary of a farm or a herd or just of Daisy, I could not transfer that right to anyone. I could hire out the enjoyment of the things but I could not assign the ius utendi fruendi as such. That is why usufruct is numbered among iura personarum, rights of persons. It is a ius personae but in rem, annexed to a person (unlike praedial servitudes) but (like praedial servitudes) in rem, exigible against anyone in possession of the res. That is not a difficult statement. It merely shows that the analysis in rem/in personam has nothing to do with the question, can the right be alienated? Many systems, though as it happens not the Roman, have no difficulty with the notion of alien­ating rights in personam.

The second special point is this. Nothing that has been said implies that a right in rem must necessarily remain exigible so long as the res can be found. Some event may have intervened to extinguish the right. For example by the time I find Daisy in your hands you may (if all the facts are right) have acquired title by usucapio, extinguishing all that went before. You bought her from X and kept her for a year. X did not steal her. She was never stolen. it was a story of muddles and mistakes, not of dishonesty. Now i find her, but my right has gone. The moral of this is that one needs to say that a right in rem is one whose exigibility, so long as the right continues to exist, depends on the location of the res to which it relates.

By contrast rights in personam, though they may relate to a res, depend for their exigibility on the location of a person. Suppose that you have promised to convey Daisy to me but have not yet done so. Daisy wanders off to a third party. It is against you that I must demand my right. And if Daisy dies it does not follow that my right against you must be extinguished. That is to say, it does not follow from the nature of the right. For even when Daisy is lost or has ceased to exist it is not nonsense to affirm that you are under a legal duty to convey her to me. A right in rem cannot exist after the res has been extinguished, but a right in personam can. on the other hand just as a right in rem may be cancelled while the res still exists so a right in personarum, though capable of surviving its res, may be discharged if the res ceases to exist. It will depend on the law relating to the particular circumstances. In the case of rights in personam problems arise when the person against whom the right first arises meets his death. That is the equivalent to the destruction of the res subject to a right in rem, and the extinction of the right in personam can only be avoided by contemplating a successor as stepping into his shoes, a substitute for the original person subject to the right.

This distinction between rights in rem and in personam can be con­veniently represented by the metaphor of a legal rope or chain. Where the right is in rem the rope in your hand (the benefit end) is attached at the other end to a thing. When the right is in personam the rope in your hand is attached at the other end to a person. Whichever you have, what you actually want is likely to be a res. With the right in personam you come to the res indirectly. You give the rope a good tug to get him to give it to you. The rope represents this: he is under a duty to do something, to make some performance. Giving a res is one example. Doing work of some kind is another, as for instance building a house. Warranting, or ensuring that a state of affairs comes about or stays the case, is a third. In Latin dare, facere and praestare are the key verbs for the content of personal duties correlative to what we call rights in personam.

These ropes in rem and in personam are invisible. They are ways of representing the operation of the law, images of real forces. This leads to one final observation. Rights in rem have to be kept under close control because when people buy res they must be able to know what invisible ropes to look for. i am buying a herd of cows and you are selling. i know that i risk disappointment and trouble. i may get home and find that the cows belonged all along to X or that X had (and therefore still has) a usufruct in them. So long as there are not too many of these dangers my life as a buyer will be tolerable. But it would quickly become intolerable if effects in rem were a matter for the free operation of parties' intentions. Suppose that the owner before you wanted to be sure that the herd was never used for beef or never crossed with other breeds. If he could give himself rights in rem of that kind just as he pleased, i as buyer would have an impossible task. on the other hand if that kind of aspiration is kept off the res, the danger to commerce is avoided without completely outlawing the pursuit of such ends. He can make you promise not to sell without taking a promise from your buyer not to slaughter, not to cross-breed and so on. He thus gets a right in personam against you that you should take such a promise on re-sale. If you do not, he can tug the rope attached to you; but the res remains free. So commerce is not impeded.

The need to keep rights in rem under control is particularly strong in relation to movable property. The purchase of land is so important a transaction that the buyer can accept the need and burden of making inquiries. But even in relation to land the kinds of adverse rights in rem which he must look for are not left completely to the whim of earlier owners. For example the general characteristics of praedial servitudes constitute limits on the variety and scope of such rights. �A servitude cannot consist in having to do something' means that I cannot be surprised by the discovery that my newly bought farm owes forty days' ploughing to a powerful neighbour. That restriction forms a bulwark against dependent tenure on the feudal model.

This section has been about the difference between rights in rem and rights in personam. Obligations connote rights in personam. Indeed if we give �obligation' its English sense, in which it takes the point of view of the person subject to a duty, obligations not only connote but correlate with rights in personam. That is, right in personam is the rope viewed from one end, obligation (or duty) the rope viewed from the other. one way of saying how obligations differ from the other incorporeal things is therefore to say that while obligations correlate with rights in personam, the other incorporeal things are all rights in rem. But this, as was said at the beginning, is not quite the Roman way of seeing it. it is truer to Gaius's perception to say that usufruct and so on were �things' (like slaves, garments and so on) for the reason that, though incorpo­real, they were protected by actions in rem (pleadings directed at res rather than at persons) while obligations by contrast were the things, not mentioned as such in any actions at all, about which actions in personam were brought. The coordination of obligations with other incorporeal things was a brilliant intellectual feat. We have no reason to believe that it was not Gaius himself who achieved it.

ii. Differences between Gaius and Justinian

The threefold pattern remains the same in both: persons, things and actions. And obligations remain in things as before. But the reformed and simplified law of actions, no longer based on set patterns of claim, takes up less space in the Justinianic version. This has an effect which is less important than it might at first seem.

Gaius divided the law of things into two books, not for conceptual reasons but more to suit the book technology of his time. The three­fold division thus stretched over four books. obligations belonged in the latter part of book iii. Actions had book iV to themselves. in Justinian, obligations spill over into book IV and take 5 of the 18 titles in that book. This is only a mechanical difference. on the other hand within the law of actions a change of conceptual importance has happened, though one which cannot be pursued here. in Gaius an actio was a claim. Literally a form of words expressing a demand. The patterns of words having been displaced in favour of an omni-purpose method of claiming, what has an actio become? An action has become a right, a right of going to law to get one's due. J.4.6 pr. says: �Superest, ut de actionibus loquamur. Actio autem nihil aliud est quam ius persequendi iudicio quod sibi debetur. (it remains to speak of actions. An action is nothing other than a right of pursuing by a trial something which is due to oneself.)' We use the same not very satisfactory transferred sense. �Smith has an action on these facts' now means that Smith has a right which a court will uphold. It does not mean that there is a list of propositions proposable by plaintiffs, one of which will fit Smith's case.

iii. Outside the institutional scheme

You should not imagine that the threefold division of all law used by Gaius and Justinian in their institutes recurs in all Roman legal litera­ture. The pattern of the institutes no doubt retained a grip on the minds of all those who came to their knowledge of law by that route. But practitioners' stuff was less elegantly ordered. In particular the Edict as stabilised by Salvius Julianus under Hadrian retains the disorder to be expected of a document built up pragmatically over centuries. The matter of obligations is scattered through it. The Digest of Justinian follows an order discernibly derived from the Edict. So it too lacks a coherent pattern and does not keep obligations in one place.

2.