What defined a Jew in the context of WW2?

A look at the minutes of the Wannseekonferenz ('Wannsee Conference') might be an instructive thing to consider for this question. It is fairly long in full but perhaps the part that talks about what constituted a Jew in this context will work. The Nuremburg laws weren't the full extent of it (and yes indeed they used the term half-breeds) even for the Final Solution of the Jewish question:

In the course of the proposed final solution, the Nuremburg laws shall be the basis whereby the assumption of the completed clean up of the problem also would include the solution to mixed marriages and the half-breeds. Heydrich discussed at first theoretically the following points in view of a letter from the chief of the Reichs Chancellory:

I) Treatment of Half-breeds First-degree

Half-breeds of the first degree are in view of the final solution of the Jewish question to be equal to the Jews.

Exclude from this treatment:

a) Half-breeds first degree married to people of German blood, from which union their children (half-breeds second degree) came forth. These half-breeds second degree are essentially to be put on a par with Germans.

b) Half-breeds first degree who have received an extraordinary exemption from the highest places in the Party and the government.

Every single case has to be investigated, whereby it is not precluded that the decision may be unfavourable to the half-breed.

A prerequisite for an exemption must be based exclusively on the accomplishments of these half-breeds themselves. (Not on any merits of their German-blooded parents or marriage partners.)

Those half-breeds first degree who are exempted from the evacuations will be sterilised in order to clean up once and for all the half-breed problem and to prevent any offspring. The sterilisation is to take place voluntarily. It is a prerequisite to remain in Germany. The sterilised half-breed is from then on exempt from all laws concerning Jews to which he had been subjected up to now.

2) Treatment of Half-breeds Second Degree

The half-breeds second degree categorically are to be with the German-blooded with the exception of the following cases in which the half-breeds are put on the same footing as the Jews:

a) Descent of the half-breed second degree from a bastard marriage (both parties half-breeds).

b) Special unfavourable appearance of the half-breed second degree in which his outer appearance makes him look Jewish.[1]

c) Particularly poor record with the police and political arm of the Party of the half-breed second degree, which shows that he acts and feels like a Jew.

In these cases there shall also be no exceptions if the half-breed second degree is married to a full-blooded German.

3) Marriages between full-blooded Jews and full-blooded Germans

Each of these cases must be judged simply and determination made if the Jewish partner should be deported or if he will be sent to an old-age ghetto because of the detrimental effect on the German relatives of this mixed marriage.

4) Marriages between half-breeds first degree and full-blooded Germans

a) without children If there are no children from this marriage the half-breed first degree will be either deported or put into an old-age ghetto. (Same treatment as marriages between full-blooded Jews and full-blooded Germans, point 3).

b) with children

If there were children in the marriage which are half-breeds second degree they will - if they are put on the same footing as Jews are - be deported together with the half-breeds first degree or sent to an age-old ghetto. If in special cases those children are put on the same footing as the Germans they are to be excluded from the evacuation and with them also the half-breeds first degree.

5) Marriages between half-breeds first-degree and half-breeds first degree or Jews

In these marriages (including the children) all parties will be treated like Jews, and therefore deported or respectively sent to an old-age ghetto.

6) Marriages between half-breeds first degree and half-breeds second degree

Both marriage partners will be deported without consideration if there are children or not, or sent to an old-age ghetto. This is because children as a rule show a stronger Jewish blood content as Jewish half-breeds second degree.

SS Major General Hofmann is of the opinion that sterilisation must be widely used, particularly since the half-breed, if given the choice between deportation or sterilisation, will prefer to submit to sterilisation.

State Secretary Dr. Stuckert stated the practical execution of the above-mentioned solution possibilities to clear up the question of mixed marriages and half-breeds will cause a never ending amount of administrative work. In order to take into account also the biological facts, State Secretary Dr. Stuckert proposed proceeding to forced sterilisation.

In order to simplify the half-breed problem, further possibilities should be contemplated toward the goal that the legislature just needs to say, 'These marriages are terminated.'

It goes on but that is what it says about what constitutes a Jew with respect to deportation which of course had an ultimate outcome in most cases. And even when they're worked there was no problem in their mind if they're worked to death. What they didn't think too well about was the fact they forced prisoners to help with the manufacturing of arms which helped matters in certain uprisings e.g. the Kapo uprising of Auschwitz where they disabled a crematorium (which was what the Germans called the gas chambers).

If there are any odd things in the transcription or otherwise it's my fault; I just got the ashes back from my beloved dog who I had to put down on the 27th of January and so I was in tears for a good while.

[1] You might find the article on the BBC interesting:

http://www.bbc.co.uk/news/magazine-30811763 (The Jew who got a job offer from the Nazis). This is part speculation on my part but I wouldn't be surprised if a some part of the looks/acts/etc. like a Jew is to do with Alfred Rosenberg for his ideas were insane; then again pseudo-science is still widely used and they weren't exactly the first or the last to use that kind of rubbish 'science'; in recent time I have seen similar for identifying h*m*sexuals I believe it was. It reminded me of the above.

There is no common accepted notion of what a Jew means. Some people think it is religion, other people think that this means descendence from people who were Jews. (I do not think anyone bases this notion of citizenship of language: the population of Israel is diverse, and people called Jews can have any native tongue).

The need in strict, legal definition arises only if one wants to discriminate some category of people, as @mart wrote correctly in his/her comment. In Germany, official definition was in "Nuremberg laws", it is stated in the answer of Tom Au. Applying this definition requires some genealogy research. It was indeed applied in Germany and in some occupied countries. However in Eastern Europe this was not practical. So they used identity papers issued by the occupied countries.

As most of the Jews killed by the Germans during WWII were from Eastern Europe, it is the Eastern European definition which is most relevant "in the context of WWII".

According to the Soviet constitution "all nations were equal" and any discrimination was prohibited. But this was contradicted by the practice: Soviet interior passport (ID) had the famous "line 5": "nationality". And there it was written that you are a Ukrainian or a Russian or or a Kazakh or a Jew.

"Nationality" in Soviet Union was decided when one obtained his/her first passport (age 16) but it had to be one of the "nationalities" of your parents. So if your both parents were Jews, you had no other choice. If only one, you had a choice. I suppose that similar rules (perhaps slightly different) existed in Poland and other East European countries. Some countries wrote instead "confessionality" in the ID papers. It is these documents that the Germans used to identify the Jews in Eastern Europe in most cases.

In Israel, the notion of Jew has TWO different legal definitions. One is that makes you automatically eligible for immigration to Israel. It intentionally coincides with the Nuremberg law: one has to have at least one Jewish grandparent. The idea was that exactly those who were persecuted by the Nazis, have right for Israeli citizenship. Another definition is religious: according to the religious law, you are a Jew if your mother is Jewish, or if you converted to Judaism. This is written in your Israeli ID papers.

So you may be eligible for immigration to Israel but do not automatically become a Jew in Israel.

From what I heard (Russian with some family stories about WW2 from the Red POV), it was much simpler on the East Front from 1941 to 1943 at least. Once you are in custody of Nazis or local Nazi helpers, and:

• you are a communist
  • by admitting this
  • or having the member's book on you
  • or by declaration the local Nazi helpers, your neighbour, whatever
• you are said to be a Jew
  • by admitting this
  • or having a documents with nationality stated on you
  • or you look like a Jew
  • or by declaration the local Nazi helpers, your neighbour, whatever
• you are circumsized
  • they literally checked for this, like, "everyone, pull your pants off"

you get shot.