Article III. On Conditions Attached to a Contract

795. • A condition is a quality ¹ added to a contract, which for the most part suspends it until it is fulfilled. It is usually expressed by the particle: if, unless, provided that..., etc.

¹ Here you will define condition, rather than quality, as being a circumstance added to a disposition or contract, upon whose existence we will the validity of that disposition or contract to depend (Schmalzgr., book 4, title 8, n. 1).

A condition which can be attached to contracts is multiple, namely: 1. express or tacit; 2. concerning the present or the future; 3. possible or impossible; 4. necessary or merely contingent; 5. honorable or dishonorable; 6. potestative or casual, according as it is in the power of the contracting person or not ²; 7. positive or negative; 8. contrary to the substance of the contract, or not.

² To this partition others add a third member, namely a mixed condition, which depends partly on the choice of the contracting person and partly on an uncertain event.

796. You will resolve. - 1. All conditions must be fulfilled in that sense in which the contracting persons are prudently judged to have wished to oblige themselves.

2. A condition concerning a base or impossible thing renders the contract null both by natural and civil law. The reason is that no one can oblige himself to something base or prohibited. Nevertheless, in civil law, both common and Gallic, donations among the living and by testaments are excepted, in which base conditions are held as not added. - Cod. civ. 900. - The same must be said of a base or impossible condition added to marriage, provided it is not contrary to the substance of the contract. - Thus from Canon Law.

3. A condition concerning the present and the past does not suspend the obligation, but either at once brings it in or does not induce it, because it either exists or does not; and therefore here and now the contract is either valid or null.

4. A condition must be fulfilled not only equivalently, but in its proper form. Some except the condition, if you marry, which they say is fulfilled through entrance into Religion; for otherwise the condition would be base. - See St. Lig., n. 930. Make exception if the condition were determined to some person, e.g. if you marry Paul; because a just and honorable reason can then be present.

5. Potestative conditions, or those which depend upon the will of one of the contracting persons, are judged fulfilled not only when that is furnished which was enjoined after the manner of a condition, concerning which there can be no controversy, but even if it is not in reality furnished, namely when he who obliged himself either 1. impeded the condition from being fulfilled ³; or 2. was impeded by the other from satisfying the condition ⁴. - See Cases, n. 787 and following.

³ This does not always happen in this way; for someone can attach to a contract a condition which to fulfill or not fulfill is in the free power of the one attaching it. Thus, e.g., someone can promise marriage unless he prefers to be initiated into sacred things. Indeed this condition is tacitly understood in the contract of betrothals, namely, unless I prefer to enter religion, or receive sacred orders, etc.

⁴ You have a twofold case in which, even if that is not furnished which had been provided by the pact, nevertheless the condition is judged fulfilled: 1. if a third party, whose interest it was that it not be fulfilled, impeded the fulfillment of the condition, when the contracting person wished to fulfill it; 2. if the fulfillment was impeded by the act of a third party, in whose person the condition was to be fulfilled. - See Voet, book 28, title 7, n. 19.