Every so often, I cycle through Stamford Hill in North London, one of the largest Haredi Jewish communities outside Israel. It's common to see Orthodox Jews in shtreimel (fur hats) or fedoras, carrying prayer shawls in plastic bags or popping into Indigs, one of the many Jewish patisseries in the area. It's a strange experience for someone like me who was brought up as a Progressive Jew;1 there's a sense of kinship, but also of distance. I don't speak Hebrew, I don't attend synagogue except at Yom Kippur, and I suspect some of these Jews would not see me as Jewish (despite what I’ve been told is a “very Jewish face”). Part of the reason for this is that there is a focus, in Orthodox Judaism, on matrilineal descent. My mother's mother wasn't Jewish and to some Jews this is grounds to resist my inclusion in the community. As in many social groups, there is an interest in the “kinds of “ babies that members produce, an interest in bloodlines, in genetic inheritance and in ethnic heritage.

Such interests can be internal to the community, but rules or policies that organize baby-making can also be imposed from outside the group. Under Nazi rule, someone like me would have been classified as a “racial Jew”. The classificatory model formalized in the Nuremberg Race Laws describes degrees of Jewishness. If you have one Jewish parent, you’re “a racial Jew”; if you have two Jewish grandparents, you’re a mischling (which is German for “mixed-blood”); if you have one Jewish grandparent, you are a mischling of the second degree. Also contained in the Nuremberg Laws is the “Law for the Protection of German Blood and German Honour”.