Any process by which the male spermatozoa and the female ovum are brought together apart from and wholly distinct from an act of natural intercourse. Long used in animal husbandry, the practice presents no moral problem in the lower forms of life. The Catholic Church teaches that among humans artificial insemination constitutes such a violation of the dignity of the person and the sanctity of marriage as to be contrary to the natural and divine law. Catholic teaching on artificial insemination (among humans) was summed up by Pope Pius XII in an address to Catholic physicians (September 29, 1949). The various dimensions of the immorality involved include: in donor insemination (insemination with the active element of a donor); the third-party invasion of the exclusive marriage covenant in a kind of mechanical adultery; the irresponsibility of the donor fathering a child for which he can fulfill no paternal responsibility; and the deordination of his masturbation in order to thus donate his paternal seed. Even if insemination could be artificially achieved with the husband's semen properly collected (without masturbation) the papal teaching still points out that any process that isolates the sacred act of human generation from the beautiful and intimate conjugal union of the marriage act itself is inconsistent with the holiness and intimate personalism of that two-in-one-flesh union which alone is appropriate for the generation of a child. As long, however, as the integrity of the marriage act is preserved, various clinical techniques designed to facilitate the process are not to be condemned.