Ok, after a bit of searching here's what I've come up with.Lieju said:Isn't it both, though? There are people who identify as 'Jewish' despite having different religion, or being atheist.JDLY said:Judaism is a religion, not a race. One cannot be "part Jewish" anymore than they can be "part Christian" or "part Muslim.".
A person is obviously Jewish if they follow the Jewish faith.
Whether or not a person with, say, one Jewish parent and one non-Jewish parent (or many other similar situations) is considered Jewish has been debated for quite some time. Seemingly stemming from the fact that Judaism has, to some extent, it's own definitive culture, much like different races have different cultures.
In my opinion, however, Judaism is a religion, not a race. If both of someone's parents are Jewish, but they have chosen to be atheist, then they are not Jewish, not even part Jewish. Even if they were Jewish when they were very young and later in life became an atheist, they are no longer Jewish. However, they can sing from the mountain tops that they have Jewish ancestry, as that is completely true.
In short (and in my opinion), you are Jewish if you follow the Jewish faith, if you don't, then you're not Jewish, but feel free to state whether or not you have Jewish ancestors.