see why the men who discovered the use of fire, and selected the wild
forms of certain animals for domestication and of vegetables for
cultivation, should not find out that children of unsound constitution
were born of nearly related parents."[2]

[Footnote 2: Maine, _Early Law and Custom_, p. 228.]

Much space is given to the alleged "innate horror of incest," and
frequent appeals are made to Scripture, wrongly assuming that the
marriage of cousins is prohibited in the Mosaic Law.

The origin of "prohibited degrees" is only conjectural. The Christian
Church apparently borrowed its prohibitory canons from the Roman
Law,[3] and a dispensation is still necessary before a Catholic can
marry his first cousin. However, such dispensations have always been
easy to obtain, especially by royal families, and even the marriage of
uncle and niece sometimes occurs, as among the Spanish Habsburgs, and
as recently as 1889 in the House of Savoy.

[Footnote 3: Luckock, _History of Marriage_, p. 282.]

The prohibition of the marriage of first cousins was removed in
England by the Marriage Act of 1540,[4] but by this time the idea of
the harmfulness of kinship marriage was so thoroughly impressed upon
the people that they were very prone to look askance at such unions,
and if they were followed by any defective progeny, the fact would be
noted, and looked upon as a chastisement visited upon the parents for
their sin. Naturally the idea became proverbial, and in some places it
has influenced the civil law.