Ask the Expert: Matrilineal Descent
Why is Judaism passed down through the mother?
Question: Why is Judaism transmitted through the mother, and not the father? I'm Catholic and my fiancé is Jewish.
She says our children have to be Jewish, but I don't understand why.
Answer: You're not the only one, Bryan. A lot of interfaith couples have been wondering about this, too. And I can give you the Jewish answer to this question, but you may want to talk to your own spiritual counselor to consider how your own tradition approaches this subject.
According to traditional Jewish law (halakhah), Jewishness is passed down through the mother. So, if your mother was Jewish, you are too. This position is held by most members of the Conservative and Orthodox communities. The Reform movement recognizes the children of one Jewish parent--mother or father--as a Member of the Tribe if the child is raised Jewish. So while your children will likely be considered Jewish by Conservative and Orthodox rabbis, if you choose not to raise your children as Jews, the Reform movement might not agree. (You can read more about the contentious Who Is A Jew issue in our special section devoted specifically to this question.)
But why does traditional Jewish law favor matrilineal descent?
I've heard a few people say that Judaism goes by matrilineal descent because we always know who a person's mother is, and we don't always know who a person's father is. However, a person's status as a priest, Levite, or Israelite is passed down from the father, and such distinctions were of utmost importance in Biblical and Rabbinic times (and still, to a certain degree, today). If priesthood can be passed down via one's father, why not Jewish identity?
Prof. Shaye D. Cohen is the Littauer Professor of Hebrew Literature and Philosophy at Harvard University, and he has written a book and several articles on this issue specifically. Cohen found that matrilineal descent evolved from an original policy of patrilineal descent. In the Torah, a person's status as a Jew seems to come from his father. Joseph was married to a non-Jewish woman, and his children were considered Jewish. The same was the case for Moses and King Solomon. The change to a policy of matrilineal descent came in late antiquity.
Prof. Cohen has two theories about how this came to be. One is that the Tannaim, the rabbis who codified the concept of matrilineal descent, were influenced by the Roman legal system of the time. According to two sources from the end of the second century CE and the beginning of the third century CE, in a marriage between two Romans, a child would receive the status of his father. In an intermarriage between a Roman and a non-Roman, a child received the citizenship status of its mother.
Cohen's other theory is that the Tannaim developed matrilineal descent from an already existing conclusion about mixed breeding in the animal kingdom. The Torah prohibits the breeding of animals of different species, but there is an opinion in the Mishnah (Kilayim 8:4) that suggests that a mule whose mother was a horse and whose father was a donkey should be allowed to mate with other horses. This implies that "horse-hood" is passed down through the mother, regardless of the father's species. This concept may have been extrapolated by the rabbis to operate beyond the animal kingdom. Cohen presents both theories, but admits that neither have been conclusively proven.
Even if we don't know exactly why matrilineal descent originally emerged, it's noteworthy that nearly all Jews will consider your child Jewish. I can't tell you how to raise your children--that's something you and your fiancé will need to figure out together. But if you do decide to raise them with a Jewish identity, we hope we can continue to be of help to you!