Education and Eugenics among Jews

An unlettered Israelite should not marry a woman of priestly descent, since this constitutes in a way a profanation of the seed of Aaron. Should he marry her nevertheless, the Sages have said that the marriage will not prove successful, and he will die childless, or else he or she will come to an early death, or there will be strife between them. On the other hand, it is laudable and praiseworthy for a scholar to marry a woman of priestly descent, since in this instance learning and priesthood are united. A man should not marry the daughter of an unlettered person, for if he should die or be sent into exile, his children would grow up in ignorance, since their mother knows not the crown of the Torah. Nor should a man marry his daughter to an unlettered person, for one who gives his daughter in marriage to such a husband is as though he had bound her and placed her in front of a lion, seeing that the beast's habit is to smite his mate and have intercourse with her, since he has no shame. A man should go so far as to sell all his possessions in order to marry a scholar's daughter, for should he die or go into exile, his children would grow up to be scholars. Similarly, he should marry his daughter to a scholar, since there is no reprehensible thing or strife in the house of a scholar. (The Code of Maimonides, Book 5: The Book of Holiness, ch. XXI: 31-32, 140)