INABILITY. - Impediment to validly performing certain determined acts. To protect the common good of society, whether civil or religious, it is at times necessary that the legislator have the power to issue, among the laws regulating the juridical validity of human acts, some that can render juridically invalid acts that by their nature would be valid.
From this, however, one must not deduce that positive law prevails over natural law, because in some cases, in fact, it is natural law itself that requires, for the common good, that certain juridical acts not be absolutely valid, but be valid only conditionally upon a positive disposition of the human legislator. The latter, however, can do this not at his own arbitrary will, but only in the case that the general interest of the community requires it, e.g., to avoid frauds and damages of another kind, to protect good morals, to safeguard the interests of minors who may incur risks in aleatory contracts, to strike at clandestine marriages, to punish the crime of simony in contracts, and so on.
It is commonly admitted, both in practice and in doctrine, that both the Church and the State have the power to issue such laws. As regards the Church, this is explicitly recognized by a declaration of the Council of Trent (Sess. XXIV, de Sacramento Matrimonii, can. 4). The laws in question regulate especially the matter of contracts, wills, Marriage, the conferral of benefices, adoption, vows, religious profession, and oaths. Ecclesiastical law (cf. CIC, can. 11) removes the validity of a human act in two ways: either by directly and radically removing its validity, and then it is called irritant, or by declaring the subject incapable of performing it, and then it is incapacitating.
1. It is therefore that juridical state in which a person finds himself as a result of an incapacitating law, which causes the acts performed by that person to be rendered invalid and therefore without any effect; for example, according to cann. 1072 and 1073, clerics in sacris and religious with solemn vows or vows equivalent thereto cannot contract a valid marriage; can. 1076 establishes that in the direct line of legitimate or natural consanguinity, and in the collateral line up to the third degree, marriage is always null; can. 1075 states that those do not validly contract marriage who during a previous marriage committed adultery with a promise of marriage, or awaited even its civil form; those who committed adultery followed by conjugicide; those who together, physically or morally, procured the death of the spouse of one of the two; can. 1067 § 1 decrees that a man before completing his sixteenth year and a woman before completing her fourteenth cannot contract a valid marriage; and can. 157 says that an office vacant through resignation or deprivation following a sentence cannot, by the same Ordinary who accepted the resignation or pronounced the sentence, be conferred on family members, relatives or in-laws up to the 2nd degree, whether his own or those of the resigning party; according to can. 36 § 2, those who are excommunicated, suspended, or struck by personal interdict after a sentence are incapable of validly obtaining pontifical rescripts; according to can. 2294 § 1, those who are struck by infamia iuris cannot obtain ecclesiastical benefices, pensions, offices and dignities, which also holds, according to can. 2345, for clerics who have usurped or detain rights or goods of the Roman Church (see also cann. 2346, 2368 § 1, 2394 § 1 and 2095 etc.). In all these cases one sees therefore that the i. touches directly the person whom human positive law presupposes to be fit, by his natural right, to perform the juridical act that is invalidated by that law.
The i. can be absolute, or erga omnes, or relative. For example, the incapacity of a novice to alienate his own goods is absolute; the i. deriving from the lack of the age required to contract marriage is absolute; relative, on the other hand, is, for example, the i. of a confessor to absolve his own accomplice from a shameful sin. The i., moreover, can be imposed by a law either expressly or through words that have the same force. For example, cann. 504, 534 § 2, 2294 § 1, 2345, 2346, 2368 § 1, 2390 § 2, 2394 n. 1, 2395, 2413 expressly establish the i.; through equivalent words, cann. 1036 § 2, 222 § 1, 116, 150 § 1, 162 § 5, 171 § 3, 555, 765.
Finally, the i. deriving from a mere inhabilitans law does not oblige in conscience to omit a juridical act, but obliges only to suffer the effect of the i. imposed by that law; on the other hand, an i. deriving from a law that is not only incapacitating but also prohibiting obliges in conscience to abstain from performing juridical acts (it is not lawful, for example, to attempt marriage in the presence of a diriment impediment).
It can accidentally happen that an imposed i. has value for the external forum but not for the internal forum, for example, if it is based on a law that presupposes a fact or circumstance that in the particular case does not exist (in the case, for example, of a doubtful impediment of disparity of cult, if the party is in fact baptized, the marriage is valid in conscience).