13 Finally, it should be observed that unless the agent's services are gratuitous, the relation between him and the principal will not be agency proper, but some other kind of contract; for if a remuneration is fixed, the contract is one of hiring. And generally we may say that in all cases where, supposing a man's services are gratuitous, there would be a contract of agency or deposit, there is held to be a contract of hiring if remuneration is agreed upon; consequently, if you give clothes to a fuller to clean or to finish, or to a tailor to mend, without agreeing upon or promising any remuneration, you can be sued by the action on agency.
TITLE XXVII. OF QUASI-CONTRACTUAL OBLIGATION
Having enumerated the different kinds of contracts, let us now examine those obligations also which do not originate, properly speaking, in contract, but which, as they do not arise from a delict, seem to be quasicontractual.
1 Thus, if one man has managed the business of another during the latter's absence, each can sue the other by the action on uncommissioned agency; the direct action being available to him whose business was managed, the contrary action to him who managed it. It is clear that these actions cannot properly be said to originate in a contract, for their peculiarity is that they lie only where one man has come forward and managed the business of another without having received any commission so to do, and that other is thereby laid under a legal obligation even though he knows nothing of what has taken place. The reason of this is the general convenience; otherwise people might be summoned away by some sudden event of pressing importance, and without commissioning any one to look after and manage their affairs, the result of which would be that during their absence those affairs would be entirely neglected: and of course no one would be likely to attend to them if he were to have no action for the recovery of any outlay he might have incurred in so doing. Conversely, as the uncommissioned agent, if his management is good, lays his principal under a legal obligation, so too he is himself answerable to the latter for an account of his management; and herein he must show that he has satisfied the highest standard of carefulness, for to have displayed such carefulness as he is wont to exercise in his own affairs is not enough, if only a more diligent person could have managed the business better.
2 Guardians, again, who can be sued by the action on guardianship, cannot properly be said to be bound by contract, for there is no contract between guardian and ward: but their obligation, as it certainly does not originate in delict, may be said to be quasicontractual. In this case too each party has a remedy against the other: not only can the ward sue the guardian directly on the guardianship, but the guardian can also sue the ward by the contrary action of the same name, if he has either incurred any outlay in managing the ward's property, or bound himself on his behalf, or pledged his own property as security for the ward's creditors.
3 Again, where persons own property jointly without being partners, by having, for instance, a joint bequest or gift made to them, and one of them is liable to be sued by the other in a partition suit because he alone has taken its fruits, or because the plaintiff has laid out money on it in necessary expenses: here the defendant cannot properly be said to be bound by contract, for there has been no contract made between the parties; but as his obligation is not based on delict, it may be said to be quasicontractual.
4 The case is exactly the same between joint heirs, one of whom is liable to be sued by the other on one of these grounds in an action for partition of the inheritance.
5 So, too, the obligation of an heir to discharge legacies cannot properly be called contractual, for it cannot be said that the legatee has contracted at all with either the heir or the testator: yet, as the heir is not bound by a delict, his obligation would seem to be quasicontractual.
6 Again, a person to whom money not owed is paid by mistake is thereby laid under a quasicontractual obligation; an obligation, indeed, which is so far from being contractual, that, logically, it may be said to arise from the extinction rather than from the formation of a contract; for when a man pays over money, intending thereby to discharge a debt, his purpose is clearly to loose a bond by which he is already bound, not to bind himself by a fresh one. Still, the person to whom money is thus paid is laid under an obligation exactly as if he had taken a loan for consumption, and therefore he is liable to a condiction.