AFFINITY. — This term, derived from the Latin *affinitas* (which, according to Modestus [fr. 4, § 10, D. 38, 10], signifies the approximation of one generation to the boundaries of another), designates the legal bond that connects one spouse to the blood relatives of the other.
The rules established on this matter by Roman law (among which the principal ones are: *affinitas non parit affinitatem*; *gradu affinitatis nulli sunt*) were adopted without significant changes by both civil legislation (see, for example, article 78 of the Italian Civil Code) and ecclesiastical legislation. The latter, however, retained until the promulgation of the *Codex* the special characteristic of basing affinity not only on marriage but also on any illicit union between a man and a woman.
Under current Latin canon law (can. 97), affinity arises from a valid marriage, whether merely ratified or ratified and consummated. Whether it also arises from the marriage of two non-baptized persons and from that of a baptized person with an unbaptized person—that is, to use a more comprehensive term, from a legitimate marriage (see MARRIAGE)—is a matter of doctrinal controversy. Although affinity does not have its own lines and degrees, it is calculated in such a way that in the line and degree in which one person is a blood relative of one spouse, they are an affine of the other spouse (for definitions of direct and collateral line, as well as for the computation of degrees, see CONSANGUINITY).
In addition to constituting, within certain limits, a matrimonial impediment (which will be discussed in § 3g.), affinity produces numerous legal effects. Among these we may recall: the incompatibility with the office of administrator of ecclesiastical goods for those who are affines in the first or second degree of the local ordinary (can. 1520, § 2); the prohibition of selling or leasing, without special permission from the ordinary, the immovable property of a church to those who are bound by affinity in the first or second degree to the administrators of the church itself (can. 1540); the obligation imposed on the judge, the promoter of justice, and the defender of the bond to abstain from participating in those cases in which an affine of theirs has an interest (can. 1613, §§ 1-2); the incapacity of those who are affines of one of the parties to testify in court (can. 1757, § 3, n. 3), unless it concerns matrimonial cases (can. 1974) or causes of beatification (can. 2027, § 1). Civil law, moreover, sanctions the reciprocal obligation of alimony (see) between affines in the first degree in the direct line (Italian Civil Code, art. 433, nn. 4 and 5).
1. AFFINITY AS A MATRIMONIAL IMPEDIMENT.
The prohibition of marriages with certain relatives by affinity dates back to Mosaic legislation (Lev. 18:8, 14-18; 20:11-12, 14, 19-21; Deut. 27:20, 33), which strictly forbade marriages with a stepmother, stepdaughter, the daughter of a stepdaughter or stepson, mother-in-law, daughter-in-law, the widow of an uncle, and a sister-in-law, with the exception of the levirate marriage (see LEVIRATE, LAW OF). Roman law recognized the diriment efficacy of affinity only in the first degree of the direct line; the Church initially conformed to this provision but later extended the scope of the impediment to the seventh degree of the collateral line and, in the case of second and third marriages, introduced a second and third *genus* of affinity (see TRIGENIA), which were later suppressed by Innocent III at the Fourth Lateran Council (1215).
Today, in Latin canon law, the impediment of affinity is regulated by can. 1077 of the CIC, according to which affinity in the direct line invalidates marriage in any degree, while that in the collateral line renders it invalid up to and including the second degree. This is an impediment of purely ecclesiastical origin, whose moral foundation is to be sought both in the particular relationships of familiarity and respect that tend to arise between persons united by bonds of affinity, and in the desirability of extending as widely as possible, through marriages between strangers, the reciprocal relations of charity and friendship among human families, and finally in the need to remove occasions and dangers of seriously sinful loves. It is by its nature perpetual and multiplies: a) with the multiplication of the consanguinity from which it derives; b) with the subsequent remarriage to a blood relative of the deceased spouse. The Holy See does not usually grant dispensations from the impediment of affinity in the direct line. Dispensations are, however, easily obtainable when the impediment concerns affinity in the collateral line, especially in the second degree, which is a lesser impediment.
Affinity also constitutes a matrimonial impediment under civil law. According to article 87 of the Italian Code, those bound by affinity in the direct line and those bound by affinity in the collateral line up to the second degree (which corresponds to the first degree in canonical computation) may not contract marriage with one another.
Ferruccio Liuzzi
2. EASTERN CANON LAW
In Eastern canon law, affinity exists between each person who has had sexual relations with another and the relatives of the latter, whether this occurred in marriage (affinity from lawful intercourse) or outside of it (affinity from unlawful intercourse); affinity does not, however, exist in the case of a non-consummated marriage.The matrimonial impediment of affinity exists in the direct line in any degree; in the collateral line from lawful intercourse, up to the eighth, seventh, or sixth degree (inclusive), according to the rite; in the collateral line from unlawful intercourse, up to the fourth degree inclusive.
It should be noted, however, that Eastern non-Catholic Christians generally do not recognize affinity arising from unlawful intercourse; and for that arising from lawful intercourse, they recognize the matrimonial impediment at most up to the fourth degree.
Among the Easterners (with the exception of the Melkites), degrees are calculated according to civil computation (see CONSANGUINITY).
For affinity of the second and third *genus*, which is in force among the Greeks only with regard to the matrimonial impediment, see TRIGENIA.