Rules for determining whether or not someone is Jewish

I have often read a biography of some celebrity or another that states the religion of their father and the religion of their mother and then concludes the celibrity is either Jewish or they are not Jewish. But in many cases (in fact, it seems like in **most **cases). the author gets it wrong.

The law for determining whether or not someone is Jewish was once explained to me by an ordained rabbi as follows:

A person is Jewish if and only if … their mother is Jewish and their mother’s mother is also Jewish.

As a result, it can be said that Judiasm is a matriarchal religion - meaning it is passed down from mother to daughter.

I am not entirely certain why the law cannot be simply expressed as, “A person is Jewish if and only if their mother is Jewish”. After all, if their mother is Jewish, wouldn’t that automatically mean their mother’s mother must have also been Jewish? Or perhaps it can be more accurately stated as, “if their mother’s mother is Jewish, then their mother must have also been Jewish.”

In any case, when it comes to determining whether someone is Jewish or not, their father’s religion is immaterial. All that matters is their mother’s religion.

I hope that I have remembered and interpreted this law correctly. If I have not, I’m fairly certain that someone will be along shortly to correct my mistake.

The only reason that occurs to me why both the mother and mother’s mother are important depends on whether one of them converted from another religion to Judiasm. However, I am not at all certain how this would affect the religion of the child. Would anyone care to hazard a guess about that?

If they’d just wear those yellow stars it would be soooo much easier to tell.


That definition excludes converts. Thus it is not correct. Apart from the unnecessary “mother’s mother” thing.

I’m not sure where you heard that, but I don’t believe it’s true. Most authorities recognize anyone is Jewish if their mother is Jewish. In Reform Judaism either parent can bestow their religion to the child.

And that doesn’t cover conversion either.

I’ve never heard the mother’s mother thing. If someone converted then their children wouldn’t be Jewish under that restriction, which is certainly not the case. The children of a woman that converts before she has children are definitely Jewish in all denominations.

Reconstructionist and Reform Judaism recognize the children of Jewish fathers as being Jewish as well.

In addition to the other objections shouldn’t the person’s self-identification count? If the child of a Jewish mother tells me that they’re Catholic I’m not going to insist that they’re actually Jewish.

Self-identification of someone who is born of a Jewish mother is irrelevant. You’re born of a Jewish mother, you’re a Jew. Whatever religion you practice.

Don’t forget, Jewish is not just a religion. It also refers to race. One can be a Buddhist Jew, for example.

Um, I prefer “ethnicity”. I could be wrong about it, though.

As others have said, the “mother’s mother” thing is irrelevant. The only way I see it getting into the discussion is if someone is discussing what I believe was Hitler’s criteria for condemning someone as a Jew, which was one Jewish grandparent, so maybe in that context someone said that that’s true only if the one grandparent is the mother’s mother (which would consequently make the mother herself Jewish, which is the true critical factor).

And of course, conversion to Judaism is also possible.

I would ask them.

The only Spanish Jew I know personally (well, two, as it’s a married couple) are converts, no maternal inheritance rules apply.

There was a recent article in a weekly about this German-born, raised-in-Catholic-Spain woman whose parents told her they were Jewish when she became of age (at 23): she is ethnically Jewish, and she’s been able to find some of her lost relatives… but the article made no mention of her religion, nor of the religion of her husband and children. The Koplowitz sisters (among Spain’s biggest fortunes) are the daughters of a German, Jewish father and a Spanish mother - are they Jewish? Dunnow, I haven’t asked them and they haven’t told me. By Spanish criteria, all three women “have Jewish ancestry” but anything beyond that is considered self-identification, you ask them.

Rule #1. Do not try to determine whether someone else is Jewish.

Rule #2. If someone tells you they are Jewish, take their word for it.

Rule #3. If someone tells you they are not Jewish, take their word for it.

That may be a useful set of rules for the general run of mankind, but it’s not really workable for every single person. An Orthodox girl who wishes to marry would not be well-served, for example, by following your advice. A person who seeks to invoke Israel’s “Right of Return,” law is likewise not well-situated to advise the Israeli authorities that they are permitted to immediately claim Israeli citizenship under Boyo Jim’s Rule #2.

While the OP is certainly confused with the “mother’s mother,” business, I sense he’s looking for an actual, fact-based answer.

And there are several possible answers that can be given, but all of them have a bit more rigor than Boyo Jim’s proposed framework.

A Reform answer is: a child of a Jewish parent is presumed Jewish. “This presumption of the Jewish status of the offspring of any mixed marriage is to be established through appropriate and timely public and formal acts of identification with the Jewish faith and people. The performance of these mitzvot serves to commit those who participate in them, both parent and child, to Jewish life.”

At the other end of the scale, an Orthodox answer is: a child is a Jew if his mother was Jewish.

As to conversions, all major schools of Judaism treat a convert precisely the same as a born Jew. But the process of conversion is quite different, so much so that the Orthodox do not recognize a Reform conversion as valid. Orthodox conversions require the male convert to undergo b’rit milah/ – circumcision – or hatafat dam b’rit, a small pinprick to draw a drop of blood if the subject is already circumcised. Orthodox converts must fully immerse themselves in the mikvah, a bath of ritual cleaning called tevilah. Reform converts are not required to undergo any of these.

All converts agree to accept the “yoke” – the burden – of obeying the mitzvah, the commandments. But an Orthodox convert is promising a literal acceptance of Orthodox rabbinic authority insofar as the 613 mitzvah are concerned; a Reform convert’s promise reaches only those mitzvot which his independent study and reasoning guide him to follow.

So tl;dr: there are different authorities who will give somewhat different answers to the question, “Who is a Jew?” None of them, except perhaps the Nuremberg laws, use the standard of the mother and the grandmother.

There is really no situation in which you need to determine if someone else is Jewish. If you’re talking about a famous person, it’s not that hard to consult Wikipedia or another resource: you can see what faith their parents belonged to and how they identify themselves.

The OP has the official definition of Judaism essentially correct, but as a practical matter, many Jews are more than willing to water down the rules and embrace celebrities or heroes with a little Jewish blood as part of the tribe.

Strictly speaking, heavyweight champ Max Baer didn’t qualify as Jewish (his mother was Scotch-Irish and his father was only half-Jewish), but he identified as a Jew and wore a Star of David on his trunks while knocking out Aryan Max Schmeling. That was more than enough to make most American Jews accept him as plenty Jewish enough.

Many Jews are largely areligious, and don’t particularly care about traitional rules for defining Judaism. To them, if (hypothetically) Ken Greenberg grew up in Manhattan, went to Stuyvesant High School and NYU, became a lawyer, eats Chinese food, and likes Woody Allen, why… he’s Jewish, even if his mother was Italian and he’s never set foot in a synagogue in his life.

In any case, I’m pretty sure Hitler never freed anyone from Auschwitz on the grounds that their mothers weren’t Jewish or that they themselves weren’t observant. If you’re Jewish enough for bigots to hate you, you’re Jewish enough.


Jewish enough for what, exactly?

Really, the most accurate label (if label one must) is “tribe” (or “nation” in the original, pre-nation-state sense - which is the term often used in the Bible).

“Race” is not accurate, because Jews vary by race (there are White Jews and Black Jews).

“Ethnicity” isn’t accurate, because it is possible to choose to be Jewish, by conversion. Ethnicity is usually a given.

“Tribe”, on the other hand, is a status conferred by the rules of the tribe - whether by getting the tribe to accept you as one (conversion) or by being born to the right type of tribal member.

What if the family only has boys? There children and there whole family line from then on can’t be Jewish? Unless the boy gets married to a Jewish lady and she has a girl.

That definitely doesn’t sound right as others have said.

Well, almost. Typically every Jewish person has a Jewish mother, as Judaism historically has been passed down mother to child. If a Jewish boy married a non-Jewish woman, that child wouldn’t be considered Jewish unless they (the mother or the child) converted.

Happily, for Reform and Reconstructionist Jews, patrilineal descent is accepted. Soon, I think, the Conservative movement will catch up. The Orthodoxy never will, I imagine.

probably Chinese.