Definition: What is an Obligation?

Justinian's Institutes bravely give a definition as soon as they begin to consider obligations. So J.3.13 pr. says this:

Nunc transeamus ad obligationes. Obligatio est iuris vinculum, quo necessitate adstringimur alicuius solvendae rei, secundum nostrae civitatis iura.

Now let us move on to obligations. An obligation is a bond of law, by which we are tied down to the necessity of making some performance, according to the laws of our state.

it is convenient to begin with the point which is made at the end: �according to the laws of our state'. Whatever precisely an obligation is, lawyers are only interested when it is a phenomenon recognised by their legal system. If someone gives you a present, it makes sense to say that you are under an obligation to say thank you. Similarly, when you are far from home you are under an obligation to keep in contact with your family. You recognise it perhaps only in the breach, from mental energy spent in putting off the necessity which ties you down. But these are moral obligations. The law has nothing to say about their breach. in the conventional language of modern jurisprudence they belong to a different normative system, morality, not law. The word �normative' and its noun, which is �norm', come from the Latin �norma', which is a carpenter's T-square, just as a �regula' is his ruler. The metaphor is the same in both cases. The words which name the tools which guide the carpenter in giving shape to his material also serve to name the standards which guide people in moulding their behaviour. A norm is a rule or standard of that kind, used to mould behaviour. it tells you what you ought to do. And you have to see what kind of �ought' is in question. There are different normative systems. Morality is one. Etiquette may be another. Or perhaps it is only a department of morality. Law is yet another.

That tells us nothing about the definition of obligation. It only says that, whatever it may be, we are not interested in any non-legal manifestation which the phenomenon may have.

The next words to be considered are... iuris vinculum, quo... adstringimur. First, vinculum. This comes from the family of words round the verb vinare, meaning �to bind'. A vinculum is anything with which binding is done. Hence, a fetter, bond, chain or rope. in the translation which I gave I used �bond’ but I almost prefer �rope’ or �chain’. Then adstringimur. This is another word of binding. Adstringere means �to tie up tightly’, �to confine with bonds’. So the metaphor in the definition is a man tied down by a rope or chain. It is an image not confined to vinculum and adstringimur. For it is in obligatio too. You know words like �ligament’ and �ligature’. They come straight from ligare. Less obviously, also the French lier and English �liable’. Ligare means much the same as the other verbs, �to tie’ or �to fasten’. The metaphor crops up in one other place as well, in the verb solvere. We will come to that in a minute.

So far we have this. An obligation is a rope... by which we are tied... Dwell on that image. Here am I with a rope around my neck. We must allow for the other end of the rope. You are holding that. I am under an obligation to you: the picture is of this rope between us, and you in control; the rope is round my neck but in your hand.

An obligation is a bond (rope, chain) of (in) law by which we are tied... according to the laws of our state.

The words missing are necessitate alicuius solvendae rei. The order jumps around because it is different in each language. In the first translation these words are �the necessity of making some perform­ance'. And they are joined into the sentence just given with the extra words �down to'. The translation says that we are �tied down to the necessity' and so on. This is not easy.

Start again with the phrase alicuius solvendae rei. Solvere is an aston­ishing word. The oxford Latin Dictionary gives it twenty-two distinct senses. The beginning is �to loosen', �to untie', �to release'. You can see how it completes the metaphor in obligatio, from the other end of the story. The rope is untied, released. Obligationem solvere is �to discharge an obligation', the tie untied. But that sense is not immediately present in this sentence. it is no more than a deliberate overtone. For solvere also applies, not directly to the obligation itself, but to the performance which is the content of the obligation. That is, to the performance which will, when made, effect release from the vinculum iuris. The performance may be to pay money; to do or abstain from an act such as building a wall or not competing with X's business; or to render a thing (the cow Daisy) or a quantity of things (a thousand kilograms of butter).

Alicuius solvendae rei is not the easiest construction. It is all in the genitive, because it depends on necessitate, and it means �of some thing to be performed'. The word res (here rei) means �thing' or �matter'. So �a thing to be performed' covers all the variety of performances just mentioned. It is only for the sake of greater elegance that the transla­tion turns it round, into �of making some performance'. And you need consciously to add in the overtone about release: �of making some (rope-cutting) performance'.

Then there is necessitate. That is not difficult in itself. Necessitas is our �necessity', and this is the ablative �by (a, the) necessity'. The difficulty arises because the sentence makes us tied by two things at once. We are tied by the rope of law, and we are tied by the necessity of acting. This is a consequence of having in the one sentence the metaphorical force of the rope and the real compulsion of the law itself. The translation makes the transition from metaphor to reality by saying that we are tied down (by the rope) to the necessity of performing. Otherwise you have to go in for something much

longer: �An obligation is an imaginary rope of legal forces whose effect is to compel us to make some performance according to the laws of our state.'

Here are some examples. i promise, in the way which the law requires for a promise to be recognised and enforced in the courts, that on the first day of next month I will convey to you my farm, Blackacre. i am under an obligation to you to make that performance. Metaphorically, you can give the rope round my neck a good shake if I do not. In reality, pulling on the rope means going to court and putting the force of the law into operation. Again, suppose that you are standing waiting to cross the road and I carelessly drive my car over the raised pavement. And thus over your toe. I come under an obligation to repair your loss and suffering in money. Again there is the imaginary rope which is really a legal duty cast on me for breach of which the courts will give you redress. or again, suppose you pay me money by mistake. You think I worked fifty hours for you at £2.00 per hour. In fact I only worked forty hours. £20 too much. I must repay the £20. The rope which the law sees is in your hands. If I pay I regain my freedom. I release myself.

Suppose we strip away all metaphor. What is left is a relationship between two people such that one is under a legal duty to make some performance and the other has a correlative right to claim that per­formance. The word �obligation', at least in English, denotes that relationship as viewed from the standpoint of the duty.

There is more to be said about the nature of this two-ended relationship, but it is more easily done in the next section.

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