Matrilineality in Judaism

In modern Rabbinic Judaism, the traditional method of determining Jewishness relies on tracing one's maternal line. According to halakha, the recognition of someone as fully Jewish requires them to have been born to a Jewish mother.^[1] A person who is born to a non-Jewish mother and a Jewish father is regarded as Zera Yisrael (lit. 'Seed of Israel') and will only be accepted as ethnically Jewish and not as religiously Jewish. Thus, being Jewish through the paternal line typically necessitates conversion to Judaism to validate one's identity as a Jew in the fullest sense.

Matrilineal descent is observed in Orthodox Judaism and Conservative Judaism, whereas Reform Judaism and Reconstructionist Judaism accept full Jewishness through either parent; Reform responsa, however, requires an exclusively Jewish upbringing. Patrilineal descent was observed by the ancient Israelites and is still observed by the Samaritans and in Karaite Judaism, which asserts that only the Hebrew Bible by itself—that is, disregarding the oral traditions of Rabbinic Judaism—is legally and religiously binding.

Historical evidence marshalled by Professor Shaye J. D. Cohen indicates that a change from a patrilineal to a matrilineal-based principle for the offspring of mixed unions of Jew and gentile took place in the 1st century (c. 10–70 CE) times.^[2] Yet, the precise date of the shifting from patrilineality to matrilineality is disputed, according to many modern academic opinions, it was likely instituted in either the early Tannaitic period (c. 10–70 CE) or in the time of Ezra (c. 460 BCE).^[3][4][5]