5. So, too, a man may not marry his paternal aunt, even though she be so only by adoption; nor his maternal aunt; because they are regarded in the light of ascendants. For the same reason, no person may marry his great-aunt, either paternal or maternal.
6. There are, too, other marriages from which we must abstain, from regard to the ties created by marriage; for example, a man may not marry his wife’s daughter, or his son’s wife, for they are both in the place of daughters to him; and this must be understood to mean those who have been our stepdaughters or daughters-in-law; for if a woman is still your daughter-in-law, that is if she is still married to your son, you cannot marry her for another reason, as she cannot be the wife of two persons at once. And if your step-daughter, that is, if her mother is still married to you, you cannot marry her, because a person cannot have two wives at the same time.
When the affinity is dissolved
7. Again, a man is forbidden to marry his wife’s mother, and his father’s wife, because they hold the place of mothers to him; a prohibition which can only operate when the affinity is dissolved; for if your step-mother is still your step-mother, that is, if she is still married to your father, she would be prohibited from marrying you by the common rule of law, which forbids a woman to have two husbands at the same time. So if your wife’s mother is still your wife’s mother, that is, if her daughter is still married to you, you cannot marry her, because you cannot have two wives at the same time.
8. The son of a husband by a former wife, and the daughter of a wife by a former husband, or the daughter of a husband by a former wife, and the son of a wife by a former husband, may lawfully contract marriage, even though they have a brother or sister born of the second marriage.
9. The daughter of a divorced wife by a second husband is not your step-daughter; and yet Julian says we ought to abstain from such a marriage. For the betrothed wife of a son is not your daughter-in-law; nor your betrothed wife your son’s step-mother; and yet it is more decent and more in accordance with law to abstain from such marriage.
10. It is certain that the relationship of slaves is an impediment to marriage, even if the father and daughter or brother and sister, as the case may be, have been enfranchised.
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