Article Second. On the Matter of Contracts

525. What the matter of contracts is. Whatever constitutes an object of ownership, whether it is a thing, an action, or the omission of an action, generally can be the matter of a contract; but in particular some qualities are necessarily required in order that a valid contract can be entered: the matter of the contract must be possible, existing, one's own, honest, estimable by price.

1. Possible, both physically and also morally, unless someone has spontaneously wished to obligate himself even to a very difficult thing: for no one can be obligated to the physically impossible, and no one is considered to wish to obligate himself to the morally impossible unless he expressly says this.

a. Therefore if someone spontaneously obligated himself to a very difficult thing or to a heroic act, the contract, unless it is void from another source, is valid by reason of the object. But if someone obligated himself by contract to furnishing a thing which afterward from unforeseen circumstances became very difficult, he is no longer held to the contract.

b. If the matter of the contract is divisible and cannot be furnished wholly, the obligation of furnishing the possible part remains, unless from the nature of the thing or from the mind of the contracting parties it is established that they wished to be obligated either to the whole or to nothing. Yet he who by his own fault brought it about that the matter of the contract was rendered impossible is bound to repair the damage arising from this for the other contracting party.

2. Existing in fact or at least in hope, as the fruits of an orchard not yet born: for a right cannot be transferred in a thing which does not exist and is not hoped ever to exist.

526. 3. One's own, of the contracting party: for no one can transfer ownership to another which he himself does not have; therefore a donation of a thing taken away by theft is invalid.

a. If two contract concerning a thing to be furnished by some third person, the contract must be understood so that the contracting party obligates himself to taking care that the other furnish the thing; otherwise he would enter a contract not about his own deed but about the deed of another.

b. A contract can be made concerning a thing which at the time at which the contract is made is still in the ownership of another, provided it will be in the ownership of the contracting party; yet modern laws nearly all declare invalid the sale of an inheritance which is expected from a person still living.¹

4. Honest and licit: for there is no obligation to a dishonorable or illicit action; otherwise there would be an obligation to do and omit the same thing at once. Wherefore contracts concerning an evil thing induce no obligation, for example, concerning committing homicide, theft, etc.

For the value of the contract it suffices that the thing be honest as to substance, although some accidental circumstance is illicit; in which case the contract concerning an honest thing is illicitly perfected. Thus the sale of arms against the prohibition of the republic is valid but illicit.

5. Estimable by price, if the contract is made concerning a thing to be exchanged for a price. That is estimable by price which for one is burdensome or which deprives him of an advantage, but for another is useful or delightful. Wherefore he unjustly demands money who shows the way to one passing by, because the labor necessary for this is less than can be estimated by price; and in like manner contracts concerning a thing altogether useless have no force.

a. Therefore estimable by price is not only a thing or action which someone assumes is to be furnished, and an advantage of which someone deprives himself, but also an obligation which someone takes on himself.

b. Nothing prevents spiritual things from being able to constitute the object of a contract, whether gratuitous or onerous, provided simony is avoided, that is, provided they are not exchanged for a temporal price. Thus concerning prayer or Mass a promise, donation, or exchange with another spiritual thing can be made.

¹ G.A. Section 879.

527. Whether a contract concerning a thing already owed from another source is valid, so that it is permitted to receive payment for it.

a. A contract cannot validly be made concerning a thing which is already owed from justice to the other contracting party, because the contract would be made concerning the transferring of a right which the other already has independently of the contract. Thus a judge cannot enter a contract of accepting something for giving a just sentence, nor a finder for restoring a thing found.

b. But a contract can validly and licitly be made concerning a thing which is already owed from justice to a third person, if it also profits another in such a way that it does not harm the former. Therefore for the same action someone can receive the whole price from several by agreement: for the work which he furnishes is worthy of a price and is not less useful to several than to one.¹

Thus he who has been hired by Peter to undertake a journey for the sake of some business can also receive from Paul the price of the same journey, if he can at the same time accomplish his business too. For although the journey is already owed to one from justice, nevertheless it is not owed to him according to its whole value, but only insofar as it is required for the end for which he was hired by Peter.

c. Of itself valid, but illicit, is a contract concerning a thing which is already owed to the other contracting party from charity or from another virtue, as if a physician or advocate demands a price from a poor man to whom from charity he is bound to furnish his work gratuitously: for by the contract entered the poor man can demand the work not only from charity but also from justice, which is estimable by price.

d. Valid and of itself also licit is a contract concerning a thing already owed from another title or from another virtue, but not to the other contracting party, for example, concerning hearing Mass on a feast day, concerning laying aside hatred: for to the price corresponds the right which the other contracting party acquires and did not have before. Yet he who is so disposed that he would not furnish the thing owed unless the price were paid sins by this act of will; but the contract is valid.

¹ Cf. Holzmann, Theologia moralis, t. 4, n. 279.