3.1.99 to 3.1.102

(89) And first, let us examine those which arise from contracts, of which there are four different kinds; for an obligation is contracted either by delivery of property, verbally, by writing, or by consent. (90) An obligation by the delivery of property is contracted, for example, in the case of a loan for consumption. This generally takes place with reference to articles which are susceptible of being weighed, counted, or measured; such as money, wine, oil, grain, bronze, silver, and gold. This kind of property we transfer either by counting, measuring or weighing it with the understanding that it shall belong to him who receives it, and that, at some time or other, not the same article, but another of the same nature, shall be returned to us, and therefore an obligation of this kind is called mutuum ,because what was given to you by me, from being mine becomes yours. (91) He also who received something that was not due from a person who paid him through mistake, is liable under a contract of this description, for a personal action can be brought against him under the formula, "If it appears that he was required to give"; just as if he had received the property as a loan for consumption. Hence certain authorities hold that a ward or a woman to whom payment was made of something which was not due, through mistake, and without the authority of his or her guardian, is not liable to a personal action; any more than they are for a loan for consumption. This species of obligation does not, however, appear to arise from a contract, for a party who gives with the intention of paying a debt, rather desires to discharge an obligation than to incur one.