I always thought of it as a religion, that people accept and sometimes convert to. Somebody I know tried to argue that it was a race and then talked about how they have distinct features (black curly hair, olive skin, big ears and noses). I thought this was ridiculous since the American Jews that I know look nothing like that. More Italians and Spaniards fit that description. Generally Jews just look like the rest of the people in that country. White in the Us, tan in Palestine, black in Ethiopia.
The only argument that I can understand is how some Jews have distinct names (Goldberg, Silverman, Cohen). But this doesn't have to mean anything. These could be other Orthodox Judaism says that Jewishness is passed down through the mother. If the Jew converts they are still considered a Jew. This is just their belief though.
The only argument that I can understand is how some Jews have distinct names (Goldberg, Silverman, Cohen). But this doesn't have to mean anything. These could be other Orthodox Judaism says that Jewishness is passed down through the mother. If the Jew converts they are still considered a Jew. This is just their belief though.