§ 4. On the External Form of Contracts

259. By natural law it suffices that contracts be effected by the legitimate and clearly manifested consent of the contracting parties. But by positive laws (whether ecclesiastical or civil), some determinate form or solemnity is often established under pain of nullity. But are contracts entered without that form which is held essential in the external forum valid? If the essential form required by ecclesiastical law is lacking, then the contract is null even in the forum of conscience. Hence, e.g., espousals, matrimony, alienation of ecclesiastical goods, etc., made without the essential form established by the Church are invalid. But if there is question of an essential form required by civil laws, then there is a threefold opinion: the first affirms validity; the second denies it; the third says that the matter is doubtful, since so many authors of great name dispute on either side, and therefore that the possessor is to be preferred until he is condemned to restitution by decree of a judge. Certainly this third opinion is to be followed in practice;⁵¹ but the second opinion, denying validity when the essentially prescribed form is lacking, seems to us more true. For if ecclesiastical law can declare certain contracts null unless they were entered under a determinate form (e.g., espousals, religious profession), there is no reason why the same right should not be granted to civil law in purely material contracts. Hence authors most commonly grant such an invalidating faculty to the civil power.

The only doubt remaining is whether the civil power truly intended to annul contracts without the prescribed form. But this is a mere question of fact. When civil law simply and without any restriction declares those contracts null, the words of the law are to be taken as they sound, and the contracts are to be held as null. Thus also Lugo.⁵²

⁵¹ Cf. St. Alphonsus, Theol. mor. l. 3, n. 711.

⁵² De iust. et iure disp. 22, n. 252.