TITLE XIII. OF OBLIGATIONS
Let us now pass on to obligations. An obligation is a legal bond, with which we are bound by a necessity of performing some act according to the laws of our State.
1 The leading division of obligations is into two kinds, civil and praetorian. Those obligations are civil which are established by statute, or at least are sanctioned by the civil law; those are praetorian which the praetor has established by his own jurisdiction, and which are also called honorary.
2 By another division they are arranged in four classes, contractual, quasicontractual, delictal, and quasidelictal. And first, we must examine those which are contractual, and which again fall into four species, for contract is concluded either by delivery, by a form of words, by writing, or by consent: each of which we will treat in detail.
TITLE XIV. OF REAL CONTRACTS, OR THE MODES IN WHICH OBLIGATIONS ARE CONTRACTED BY DELIVERY
Real contracts, or contracts concluded by delivery, are exemplified by loan for consumption, that is to say, loan of such things as are estimated by weight, number, or measure, for instance, wine, oil, corn, coined money, copper, silver, or gold: things in which we transfer our property on condition that the receiver shall transfer to us, at a future time, not the same things, but other things of the same kind and quality: and this contract is called mutuum, because thereby meum or mine becomes tuum or thine. The action to which it gives rise is called a condiction.
1 Again, a man is bound by a real obligation if he takes what is not owed him from another who pays him by mistake; and the latter can, as plaintiff, bring a condiction against him for its recovery, after the analogy of the action whose formula ran 'if it be proved that he ought to convey,' exactly as if the defendant had received a loan from him. Consequently a pupil who, by mistake, is paid something which is not really owed him without his guardian's authority, will no more be bound by a condiction for the recovery of money not owed than by one for money received as a loan: though this kind of liability does not seem to be founded on contract; for a payment made in order to discharge a debt is intended to extinguish, not to create, an obligation.
2 So too a person to whom a thing is lent for use is laid under a real obligation, and is liable to the action on a loan for use. The difference between this case and a loan for consumption is considerable, for here the intention is not to make the object lent the property of the borrower, who accordingly is bound to restore the same identical thing. Again, if the receiver of a loan for consumption loses what he has received by some accident, such as fire, the fall of a building, shipwreck, or the attack of thieves or enemies, he still remains bound: but the borrower for use, though responsible for the greatest care in keeping what is lent him—and it is not enough that he has shown as much care as he usually bestows on his own affairs, if only some one else could have been more diligent in the charge of it—has not to answer for loss occasioned by fire or accident beyond his control, provided it did not occur through any fault of his own. Otherwise, of course, it is different: for instance, if you choose to take with you on a journey a thing which has been lent to you for use, and lose it by being attacked by enemies or thieves, or by a shipwreck, it is beyond question that you will be liable for its restoration. A thing is not properly said to be lent for use if any recompense is received or agreed upon for the service; for where this is the case, the use of the thing is held to be hired, and the contract is of a different kind, for a loan for use ought always to be gratuitous.