INCEST. – I. NOTION. – From incestu (non castus), it is the carnal sin between blood relatives or relatives by marriage who, according to natural and ecclesiastical law, cannot validly contract Marriage with one another (v. AFFINITÀ; CONSANGUINEITÀ).
S. Agostino rightly observes that, if at the beginning of the human race the union between brothers and sisters was a necessary condition for the propagation of the human race, once this necessity had ceased, such a union was condemned by religion (De civit. Dei, l. XV, cap. 16, n. 1: PL 41, 457–58). Consequently, at the beginning of the human race, the union between brother and sister must not be regarded as an incestuous union, since the Creator had so ordained it for the propagation and preservation of the human race.
II. HISTORY. - I. Among Primitive Peoples. - For a long time, considering the totemistic culture of Australia the most ancient, it was maintained that the oldest form of the prohibition of incest is that of the totemic clan, defined by Durkheim as “a group of individuals who regard themselves as relatives of one another, but who recognize this kinship exclusively by this most particular sign, namely, that they bear the same totem” (v. TOTEMISMO). In short, it was assumed that the earliest humanity, not knowing marriage, lived in sexual promiscuity and then, in order to remedy this, divided the clan, first into two and later into several marriage classes, through the law of exogamy. Hence the prohibition of incest. Frazer explains it clearly as follows: “Put briefly, the two-class system has the effect of prohibiting marriage between brothers and sisters, but not always marriage between parents and children, nor between the children of a man and those of his sister. The four-class system has the effect of prohibiting marriage between brothers and sisters and between parents and children, but not marriage between the children of a man and those of his sister. Each subsequent dichotomy therefore has the result of removing a new class of relatives from the list of persons with whom marriage may be contracted, that is, of adding one more to the list of prohibited degrees.” This purely evolutionist theory has been superseded by modern ethnology through broader and more precise research, from which it appears that the oldest form of marriage, as the great scholar of the psychology of peoples W. Wundt already acknowledged in 1912, is monogamy, and that the social organization of the Australian totemists, together with the prohibition of incest associated with it, is not the most ancient.
Today, in accordance with the great advances made by the sociology of primitive peoples within ethnology, many forms of the prohibition of incest must be distinguished. The totemistic form is only one among the many forms that vary in scope and effects, just as the various characteristic forms of kinship by consanguinity and affinity vary, with which the prohibition of incest is closely connected (v. PARENTELA). The Andamanese, for example, counted three generations of relatives; they observed the exogamy of an extended family: parents, children, and the children of the children, the grandchildren; in the collateral line: brothers and sisters and their offspring. There was no prohibition against marrying a person of the same name, whether that person belonged to another tribe or to their own community. This is more or less the case among the hunting and gathering peoples, who are ethnologically the most ancient of humanity. Among the Mongols, on the contrary, the prohibition of incest encompasses many generations of consanguineous relatives, that is, all the persons of the clan, until, in case of necessity, it divides in order to form a new exogamous unit; thus the clan often practically corresponds to a tribe having a large number of generations of consanguineous relatives. Kinship by affinity, on the other hand, ends at the first degree, because marriage between first cousins, the children of a brother and a sister, is permitted. This is generally the case among nomadic pastoral peoples.
It would be too lengthy to discuss the other characteristic forms of incest; it need only be noted here that one form of the prohibition of incest is universal, that is, it is observed among all peoples. It concerns consanguineous relatives in the direct line, and, with some variation, in the collateral line, as well as the closest relatives by affinity. Among these relatives, incest is regarded as a grave offense and is often punished by death.
In judging incest, primitive peoples are guided by their moral sense, and consequently clearly distinguish the legal prohibition of incest, which may encompass many generations, from the moral prohibition. This was noted by Fr. Schebesta among the Pygmies of Kivu; by Shirokogoroff among the Tungus and Manchurians; by Malinowski among the inhabitants of the Trobriand Islands in Melanesia; and it may likewise be observed among peoples belonging to the Tibeto-Chinese linguistic family. Thus, among the latter, as well as among the Tungus and Manchurians, a new exogamous unit may be formed by dividing the patrilineal descendants who can be traced to a common ancestor within five degrees of kinship, counted according to the Chinese system, that is, beginning with one’s own person. This returns us to an extended family: parents, children, and the children of the children; three generations of consanguineous relatives. After distinguishing seven degrees of aversion to incest among the peoples he explored, Malinowski expressly points out that there can be no doubt that the tabu separating members of the same family is, in the reality of tribal life, if not in legal theory, a distinct force, added to the exogamous tabu. Its influence is apparent not only in the separation of father and daughter, but also in the fact that incest with one’s own mother and sister arouses a moral indignation (it is punished by death) incomparably greater than incest with a cousin, not to mention incest with a “classificatory” mother and a “classificatory” sister, which is easily condoned.
The study of kinship shows that peoples distinguish and recognize the ancestor of the family, the clan, the tribe, the people, and all humanity; yet of these ancestors only the last, the nearest, together with his offspring, is the object of the strictest prohibition of incest, and this prohibition is truly universal. The same is true of collateral consanguineous kinship in relation to universal human brotherhood, and of kinship deriving from the various ancestors. Kinship by affinity is judged in a manner analogous to kinship by consanguinity.
How is the prohibition of incest to be explained? A distinction must be made between the explanation of the particular forms of this prohibition, linked to the various types of kinship, and that of the universal prohibition. The particular forms are explained by the formation of the type of civilization to which they belong; the latter, instead, comes down to the question of why marriage and every sexual relationship between parents and children, and between brothers and sisters, are prohibited.
Once Durkheim’s explanation has been set aside—according to which totemism gave rise to the belief that blood, especially women’s menstrual blood, is the seat of magical powers, a belief that he regards as the primary cause of exogamy—especially since the prohibition of incest appears to precede magical beliefs, and since the evolutionist theory of primitive sexual promiscuity is untenable, the explanations of McLennan, founded on female infanticide, and of Lord Avebury, based on the abduction of women, and so forth, also collapse.
Westermarck, Darwin, Havelock Ellis, and Crawley proposed a psychological explanation, according to which, among persons—especially relatives—who live and grow up together from the earliest age, the impulses leading to the passion of love and to marriage do not develop at all, or develop only with difficulty. This explanation, as Fr. Schmidt rightly observed, may at most serve to justify the prohibition of incest between persons of the same age or generation, but not that between parents and children, which is the gravest and most universally detested form. There may be some truth in it: the lack of sexual attraction that can lead to marriage is even greater when there is an age difference between ascendants and descendants. But in reality the deeper reason is moral: the fact that parents must exercise their authority prevents them from marrying their children; the children’s reverential fear of their parents does not allow the desire to unite in marriage with their parents to arise in them. The ethnologist knows well how important the elders are in primitive societies, where youth counts for little or nothing and must learn and receive everything from the elders.
The ethical nature of exogamy among close relatives then becomes entirely clear from the prohibition of i. between close relatives by affinity.
The reason given by primitive peoples for the prohibition of i. is a religious one. Thus the Semang of the Malay Peninsula, when an i. or an adultery is committed, say: Lavaid Karé, that is, a sin against Karé (God). Similarly, among the Tungus, when it is necessary to form a new exogamous unit by dividing the clan, after counting five generations, a sacrifice is made to Buga, the Supreme Being, author of the moral order, in order to announce to him the fact of the exogamous division.
The prohibition of i. must have existed from the very beginnings of humanity. If the unity of origin of the human race from a first human couple is admitted, as most anthropologists, ethnologists, and linguists today maintain, one must also necessarily admit that the first marriages were between brothers and sisters. This, however, not in the sense understood by the evolutionists, who postulate a primitive promiscuity of the sexes, but as an exception to the rule, an exception demanded by necessity, since the prohibition of such marriages must then have intervened immediately. This is indicated by many considerations. The family, as Fr. Schmidt rightly observed, is centripetal in itself, tending inward, whereas society, in order to grow, requires a centrifugal tendency. Now, if exogamy among close relatives had not existed at the beginnings of humanity, the source of the increase of the human race would in time have already dried up physically, owing to the infertility of marriage. This is observed among peoples reduced to small numbers, as, for example, among the Ainu, in whom extreme nervous irritability develops and who are heading toward rapid extinction.
From the moral point of view also, in the absence of the prohibition of i., parental authority would have disappeared, as has been said. With this, the most powerful foundation of every true culture would have been destroyed; tradition, through the transmission of what previous generations had done, would have become impossible.
From the strictly social point of view, moreover, the consequences of i., observes the same Fr. Schmidt, would have been fatal. Those great social groupings that are indispensable to the full development of all human faculties could never have arisen.
Ethnologically, from the uniformity of form of the prohibitive law concerning i., which has been described as universal, one infers its existence at the beginning of humanity. Indeed, if the prohibition of i. in this form had not existed from the beginnings of humanity, but had been devised after the separation from the common centre, there would have been not one but multiple forms of prohibition of i., as is observed among the various types of civilization.
BIBLI: E. Durkheim, La prohibition de l'inceste et ses origines, in Année sociologique, 1 (1896-97), pp. 1-70; E. Crawley, The mystic rose. A study of primitive marriage, London 1902; I. G. Frazer, Totemism and exogamy, there 1911; W. I. Thomas, Sesso e società, Turin 1911; W. Schmidt-W. Koppers, Völker und Kulturen. Gesellschaft und Wirtschaft der Völker, Regensburg 1924, p. 152 ff.; E. Westermarck, History of human marriage, II, London 1925, chap. 19; H. Töben, Über Inzest, Vienna 1925; Br. Malinowski, Sex and repression in savage society, London 1927; J. G. Frazer, L'homme. Dieu et l'immortalité, French translation, Paris 1928, p. 109 ff. and passim; Br. Malinowski, The sexual life of savages in North-western Melanesia. An ethnographic account of courtship, marriage and family life among the natives of the Tiberian Islanders, British New Guinea. With preface of Havelock Ellis, there 1929, pp. 384, 389, 416, 451; F.R.S. Raglan, Incest and exogamy, in Journal of anthropological Instinct, there 1931; E. H. Slan, The Adumani islanders, reprint, there 1932, pp. 38-59, 67-68; I. M. Cooper, Incest prohibitions in primitive culture, in Primitive man, Washington 1932; L. Vannicelli, La famiglia cinese. Studio etnologico, Milan 1943, p. 93 ff. and passim; id., L'unità del genere umano, in Morale e biologia, there 1944, p. 1536; W. Schmidt, Secke Bücher von der Liebe, von der Ehe, von der Familie, Lucerne 1945; M. Schulien, L'unità del genere umano alla luce delle ultime risultanze antropologiche, linguistiche ed etnologiche, 3rd ed., Milan 1946; P. Schebesta, Die Bambuti-Pygmiden von Isuri. Ergebnisse zweier Forschungsreisen zu den zentralafrikanischen Pygmiden, II, Brussels 1948, p. 357 ff.; W. Koppers, Der Urmensch und sein Weltbild, Vienna 1949, pp. 35-42; L. Vannicelli, La parentela di consanguineità e di affinità e la proibizione dell'i., in Atti del XIV Congresso internazionale di sociologia, Rome 1950, Luigi Vannicelli
2. Jews. — In Gen. 19:31-38, Lot’s i. with his two daughters is recalled in order to condemn II. Then, in the Mosaic legislation, unions were prohibited between a mother and her son, a son and his father’s wife, a brother and his uterine or full sister, a grandfather and his granddaughter, a nephew and his father’s or mother’s sister, because, as the law observes, they concern the same flesh (Lev. 18:7-15). Among relations by affinity, unions were prohibited between a nephew and his uncle’s wife, and between a father-in-law and his daughter-in-law (ibid. 18:14-15). The penalties established against those guilty of incest were severe: thus anyone who sinned with his stepmother, daughter-in-law, stepdaughter, or full or uterine sister was to suffer the death penalty together with the woman (ibid. 20:11, 12, 14, 17). Of the nephew who commits i. with his paternal or maternal aunt, it is said that together with the woman he shall bear the penalty of his crime (the penalty is not specified). If anyone defiles himself through i. with his paternal or maternal uncle’s wife, he shall die with her childless (ibid. 20:19-21). In Deuteronomy, curses are pronounced against those guilty of incest, and the gravest cases of i. are recalled (Deut. 27:20, 22-23).
Sacred Scripture also recalls the incestuous relations of Ammon, son of David, with Thamar, sister of Absalom (II Sam. 13:11-22), and of Absalom with David’s concubines (ibid. 16:21-22), etc. St. John the Baptist was imprisoned for reproving Herod Antipas, who, contrary to the law, had taken as his wife the wife of his living brother Philip (Mc. 6:17-18).
3. Romans. — In ancient Roman law, in addition to union with a Vestal, every union between persons among whom there existed a prohibition of marriage was considered i.; this prohibition was based on that complex of traditional and religious norms known by the name of fas. Even in the lex Iulia de adulteriis, according to recent doctrine, the concept and cases of i. are traced back to the veteres mores (cf. D. 23, 2, 29, 1); in the classical period, however, not all violations of marriage prohibitions constituted i., some of them falling within the concept of stuprum. On the basis of this new concept, i. consisted in union between ascendants and descendants, even when the relationship was only adoptive; union between brothers; union with a paternal or maternal uncle or aunt; and union between relatives by affinity in the direct line, even after the dissolution of the marriage that had created the affinity. Alongside these indisputable cases, it is probable that classical jurisprudence placed others, such as, for example, the union of one spouse with children subsequently born to the other spouse after the divorce, and that of a son with his father’s concubine.
The imperial legislation of the post-classical period established new marriage prohibitions that can be connected with the ancient ones established by the mores and thus included within the concept of i.; thus unions were prohibited between relatives by affinity in the collateral line within the second degree, between cousins, and, through the influence of the new religion, between Christians and Jews.
According to recent scholarship, no great importance should be attached to the distinction between i. iure civili (prohibited legibus) and i. iure gentium (prohibited moribus), a distinction that is probably post-classical and originated with the constitution of Caracalla, which extended citizenship throughout the Empire, including those eastern provinces where unions disapproved by Roman custom were widespread.
III. DISCIPLINE OF CHRISTIANITY
1. Before the CIC. - At the Apostolic Council of Jerusalem, fornication—and therefore also all incestuous unions condemned in the Pentateuch—is prohibited (Act. 15:19-21). St. Paul excludes from the community of Corinth a man who had taken his stepmother as his wife (I Cor. 5:1-8). From the fourth century onward, the Councils imposed severe penalties against incestuous persons. Thus, the Council of Elvira, at the beginning of the fourth century, ordered in can. 61 that if a man married a Christian woman who was his wife’s sister, both were to be deprived of Communion for five years, except for an earlier reconciliation in case of danger of death (Mansi, II, 15-16). The Council of Neocaesarea (314-25), in can. 12, excommunicated until death the woman who successively married two brothers; and, in the event of the death of one of the parties, the other was to continue the penance (ibid., 239). The Council of Trullo (Quinisext) of 692, in can. 54, annulled incestuous marriages, excommunicating the transgressors for seven years (ibid., XI, 698). The Council of Worms of 888, in can. 32, prohibited incestuous marriages, but allowed freedom to marry when there was doubt regarding a prohibited degree. The Fourth Lateran Council of 1215, in can. 50, removed the prohibition for the third and second degrees of affinity and restricted consanguinity to the fourth degree, because of the difficulty of observing the prohibition in more distant degrees (Mansi, XI, 1035-38).2. Current canonical discipline. - The CIC has narrowed the notion of i. Formerly, affinity also arose from an illicit relationship, whereas such affinity is now excluded. However, whereas formerly a ratified but unconsummated marriage gave rise only to the impediment of public propriety, and not to i., today affinity arises from every validly contracted Marriage, even if it has not been consummated; consequently, in the case under consideration, i. would exist if two persons related by affinity committed carnal sin. There is no i. in a union between persons joined by legal relationship, however this impediment may be regarded in particular places, that is, whether diriment or prohibitive, because the bond is merely legal or spiritual.
3. Canonical penalties. - St. Paul and the Councils punished i. with severe penalties, such as perpetual or temporary excommunication, corporal punishment, prohibition of contracting a new marriage, and penance lasting several years, as can be gathered from the penitential books of the eighth and ninth centuries (H. Wasserschleben, Die Bussordnungen der abendfindlichen Kirche, nebst einer rechtsgeschichtlichen Einleitung, Halle 1851, passim; M. Schmitz, Die Bussbücher und die Bussdisziplin der Kirche, I, Magonza 1883; II, Düsseldorf 1898, passim).
The Decretals threatened anyone who contracted marriage within the prohibited degrees with excommunication latae sententiae. Moreover, Clement V canonized the civil penalties of confiscation of property, exile, and flogging. In 1869, Pius IX abrogated excommunication. The prohibition against contracting a subsequent Marriage, established by the Councils for those guilty of i., appears instead to have been abrogated by custom; certainly, before the CIC, it was no longer in force (P. Gasparri, Tractatus canonicus de Matrimonio, Roma 1932, p. 436, n. 713).
The CIC, in can. 2357 § 1, provides: «Laymen lawfully condemned... for i. are ipso facto infamous, in addition to the other penalties that the Ordinary may deem fit to impose upon them». In can. 2358, concerning Minor Clerics who become guilty of i., not only is ipso facto infamy established, but it is declared that they must be punished according to the gravity of the offense; indeed, if the circumstances are very grave, they may be dismissed from the clerical state. Can. 2359 § 2 orders that Clerics in sacris who commit i. in the first degree of consanguinity or affinity are to be suspended and declared infamous; if they hold an office, benefice, or dignity, they are to be deprived of it, and in the most serious cases they are to be deposed.
An incestuous union may become a legitimate Marriage when the impediment—if it is of ecclesiastical law—is dispensed by the competent authority. It should be noted that, in applications for dispensation from matrimonial impediments, it was formerly necessary to state the i.; otherwise the dispensation was null, until the Sacred Congregation of the Inquisition abrogated this sanction of nullity and declared that it was not even necessary to disclose the i. Today, however, i. constitutes one of the grounds for granting a dispensation in cases involving an ecclesiastical impediment.