What is commonly known today as the matrilineal principle is actually two principles rolled into one:1) The child of a Gentile father and a Jewish mother is unambiguously a Jew.2) The child of a Jewish father and a Gentile mother is unambiguously a Gentile.These two halves of the commonly assumed simple truth, "Jewish status follows the mother", have histories of their own that are relevant for how one approaches this issue today.In the Bible, there is no evidence of a matrilineal principle. Numerous sources indicate that an Israelite man who fathered a child with a non-Israelite woman could expect that child to be a part of the Israelite nation. There does seem to have been some possible stigma associated with that child--non-Israelite mothers are often singled out for mention--but no sense that they were outside of the Israelite community. For the most part, it seems safe to assume that the children of non-Israelite men and Israelite women were generally lost to the Israelite community given the patriarchal realities of the ancient world. The case of the son of an Egyptian man and an Israelite woman in Vayikra 24 seems to be the exception that proves the rule: this character unusually ended up with the Israelite community as a result of the Exodus; normally, such a person woudl not be part of the Israelite community.The first inkling we get of any sort of matrilineal approach is in the book of Ezra, where a figure known as Shekhaniah, a "son of Elam", proposes to Ezra that all of the returning exiles who have taken foreign wives cast away those wives and their children, causing them to leave the community. While the need for this edict only underscores that these people would, by default prior to this event, have been considered part of the Israelite community, this measure does seem to mark the beginning of a policy treating the children of Gentile women as Gentiles.This approach is crystallized in a clear rulingin Mishnah Kiddushin, which states that a Gentile woman produces Gentile offspring. Even this ruling met with some popular resistance, however. A few centuries later we have evidence of some in the Jewish community of Tyre wanting to circumcise such children on Shabbat, revealing their sense that "patrilineal" Jews ought to have been a part of the Jewish community. The rabbinic repsonse is fierce and clear: Such a child is a Gentile, in keeping with the Mishnah's ruling. We will see however, that the feeling that patrilineal Jews are not identical to other Gentiles resurfaces later on.On the question of the children of Gentile father's and Jewish mothers, classical rabbinic sources are divided, and a debate persists for centuries. Some sources--including the Mishnah--argue that such a child is a mamzer, a Jew, fully obligated in mitzvot, but forbidden from marrying Jews of untainted lineage. (A mamzer can legally marry only another mamzer or a convert, who also lacks pure Jewish lineage.) Others maintain the Jewishness of said matrilineal child, while either lowering the level of lineal taint--such as forbidding a daughter from such a union to marry a kohen--or claiming that no taint exists whatsoever. Rabbinic stories about such matrilineal children are suffused with a sense of liminality and conflict, with rabbis at war amongs themselves (and sometimes even with themselves) as to how to treat such children. Finally, some classical rabbinic sources may open the possibility that that the child of a Gentile father and a Jewish mother is in fact a Gentile, though if this person were to convert, they would be free of any lineal taint of mamzerut.The Babylonian Talmud's latest opinion on this matter is to reject mamzerut for matrilineal Jews.and seemingly to embrace them as full Jews (possibly with the restrictions on marrying a kohen), and the opinion that they are full Jews comes to dominate and is the ruling of the Shulhan Arukh many centuries later. But other medieval and modern voices rejected this path and maintained that a matrilineal child is in fact a Gentile in need of conversion. Sources in the 19th century continue to advance this claim, even as opposing sources try to crack down on this perspective and embrace matrilineal Jews as full, unambiguous Jews.As noted earlier, the ruling that patrilineal Jews are in need of conversion is much less controversial and accepted as black-letter law by all rabbinic authorities after the Mishnah. However, modern rabbis, including R. Tzvi Hirsch Kalischer and R. Ben Zion Uzziel have argued--based on a close reading of a number of Talmudic passages--for the classification of patrilineal Jews as zera yisrael, still of Jewish stock, such that their conversion--unlike that of their purely Gentile counterparts--is truly a reclaiming of roots and therefore to be encouraged. In other words, while conversion is still required, these authorities understand that the process is metaphysically different from that of a Gentile coming to Judaism without any genetic connection.All of this material opens of the possibility of recognizing, honoring and meeting the challenges of ambiguous identity presented to those with one Jewish and one Gentile parent. While the halakhic conversation has clearly gone in a direction that fundamentally treats matrilineal Jews as Jews and patrilineal Jews as Gentiles, there is actually much more ambiguity here than is typically acknowledged Once could imagine a model in which the standards for conversion for patrilineal Jews are dramatically lowered as they are welcomed to embrace their Jewish identity without ambivalence or ambiguity as well as demanding/respecting/honoring the need for matriineal Jews to do the same, if not with a full-blown formal conversion, than with an act of immerison in a mikveh in front of a panel of 3 as a way of satisfying the halakhic opinions that require this and being honest about the real choices that confront a person who is confronting the complexity of their own ethnic narrative and inherited faith traditions.