§ 1. Defect of Reason and Ignorance

31. • I. Defect of the use of reason.

a) Those who actually are not masters of reason, such as: infants, the completely intoxicated, those sleeping, the hypnotized, and also the insane, i.e., those who are mad regarding all things, contract matrimony invalidly. The reason is evident, because they are incapable of human acts.

b) What concerning the demented, i.e., those who are mad regarding some matter?

Resp. Most certainly they contract invalidly if they are mad precisely concerning matrimony. Otherwise, in practice, their matrimony will often be doubtful.

32. • II) Ignorance.

"In order that matrimonial consent can be had, it is necessary that the contracting parties at least not be ignorant that matrimony is a permanent society between a man and a woman for procreating children." (Can. 1089 § 1.)

a) Therefore one contracts invalidly who does not know that matrimony consists in the mutual handing over and acceptance of a right over the body in order to generation.

Certainly there is not required a precise and exact knowledge of the mode by which conjugal intercourse occurs, but it is necessary that the contracting parties know that children are generated through joined bodies, or at least that "by a certain concurrence and familiarity of the parents offspring is obtained, and is brought forth by the mother."¹ Otherwise knowledge concerning the formal object of the contract is lacking, and consequently consent into it.

¹ Vermeersch, Theologia Moralis, t. IV, n. 39.

b) In the external forum, ignorance concerning the essence of matrimony is presumed before puberty; after puberty, however, knowledge is presumed. (Can. 1081 § 2.) Yet that presumption is only of law, namely admitting proof to the contrary.

c) Any other ignorance whatsoever, besides that which regards the essence of matrimony, does not make matrimony invalid, even if, had it not existed, matrimony would never have been contracted.