I don’t see how A&E increasing the size of their family – and the number of cross-generational relationships that tie them to it – is in any way inherently destabilizing. Structures with wider bases are more stable than those with narrower ones.
If it’s not too much trouble, could you please furnish a citation for that distinction?
In any case, even if it were intrinsically evil, that would only address what Adam and Eve shouldn’t do vis incestuous relations with their offspring, not what they were capable of or actually did. It wouldn’t be the first time they sinned and it’s not like they were all that great at resisting temptation or anything.
Code:
[**Consanguinity (in Canon Law)**](http://www.newadvent.org/cathen/04264a.htm)
Consanguinity is a diriment impediment of marriage as far as the fourth degree of kinship inclusive. The term consanguinity here means, within certain limitations defined by the
law of nature, the
positive law of God, or the supreme authority of State or Church, the blood-relationship (
cognatio naturalis), or the natural bond between
persons descended from the same stock. In view of the recognized descent of all men from one common stock, there is a general blood-relationship between all men; hence the limitation mentioned has reference to the nearest root or source of consanguinity. This bond or union of blood takes place in one case through the descent of one
person from the other; this is called the direct line. In another case it takes place because the common blood is drawn from a common root, the same ancestor, from whom both
persons descend, though they do not descend one from the other, and are therefore not in a direct but in a transverse or collateral line. By the
law of nature, it is universally conceded, marriage is prohibited between parent and child, for the reverential relation between them is recognized as incompatible with the equality of relations engendered by the bond of marriage. The universal sentiment of peoples is likewise opposed to marriage between all
persons related in any degree in the direct line, thus between grandparent and grandchild.
History of impediment
Because of the acknowledged derivation of the
human race from the common progenitors,
Adam and
Eve, it is difficult to accept the opinion of some
theologians that the marriage of brother and sister is against the
law of nature; otherwise the propagation of the
human race would have begun by violation of the
natural law. It is readily understood that, considering the freedom of intercourse between such
persons, some effort would soon be made (in the interest of the social welfare) to prevent early corruption within the close
family circle by placing a bar to the hope of marriage. Hence among all peoples there has arisen a natural repugnance to the marriage of brother and sister. Some
theologians suppose herein a positive
Divine law, but it is not easy to point out any such early Divine enactment. Abraham married Sarah who was his sister by his
father, though of a different mother (
Genesis 11; cf.
Genesis 20:12). Marriage was allowed at
Athens with half-sisters by the same father (Plutarch, Cim., iv; Themist., xxxii), with half-sisters by the same mother at
Sparta (Philo, De Special. Leg., tr. Yonge, III, 306), and with full-sisters in
Egypt (Diodorus Siculus, I, 27) and
Persia, as illustrated in the well-known instances of the Ptolemies in the former, and of Cambyses in the latter, country (Herodian, III, 31). For a good summary of non-Christian customs in this respect see Melody, “Marriage of Near Kin” in “Catholic University Bulletin” (Washington, Jan., 1903, pp. 40-60).
more…
**
Question 54. The impediment of consanguinity
**and from the Jewish Virtual Library
INCEST
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In the Biblical Period
**
Genesis questions and one that isn’t
Question from Jack on 5/6/2009:
