ARTICLE II: ON MODES PREFIXED TO A CONTRACT or ON NON-PURE CONTRACTS

868. • A mode is an adjoined quality, for the most part not suspending the contract, but adding something as a burden or favor of one of the contracting parties.

Modal contracts are chiefly made 1° to a day, - 2° under a cause, - 3° under a penalty, - 4° under demonstration, - 5° under disjunction.

Resolutions. - 1° The mode must be observed from justice, unless it is repugnant to the substance of the contract.

2° Its violation ordinarily, and unless it has been agreed otherwise, does not void the contract, because it is held as something merely accidental. Hence an annual legacy made to someone with a burden to be paid in favor of the poor must be paid, although that burden is not satisfied: but one must insist by remedies of law that satisfaction be made for it. Kenrick.²

3° If the mode is base or impossible, it is held as not adjoined; nor is the contract invalid unless the mode is repugnant to its nature, or unless the will of the contracting party was altogether restricted to it.

4° In a contract to a day, the obligation arises at once, but the effect is suspended to the determined day.

5° In a contract under a cause (because), or under demonstration (I sell this, or so much), error does not invalidate unless it pertains to the essence of the thing.

6° If the error is in the quantity, the whole thing is owed if the quantity was designated demonstratively; but if taxatively, as they say, the excess of quantity is not owed. Moreover a thing is judged designated demonstratively if the thing is expressed in the first place, and afterward its quantity: for example, I leave to Titius my field of thirty acres; but taxatively, if the quantity is expressed in the first place, then the thing; for example, I leave three gold pieces in such a box. But the circumstances of things must be weighed.

7° In a contract under penalty, that is, whenever a penalty is imposed on the one withdrawing, this penalty is owed from justice, if it is sought, at least if the contract was culpably not fulfilled. Yet the penalty ought to be moderate; otherwise it would not obligate.

8° In a contract under disjunction, for example, I promise an ox or a horse, no determined thing is owed, and the payment of one removes the whole obligation. The choice of the thing of itself pertains to the debtor.