Jewish identity is the objective or subjective state of perceiving oneself as a Jew and as relating to being Jewish. Under a broader definition, Jewish identity does not depend on whether a person is regarded as a Jew by others, or by an external set of religious, or legal, or sociological norms. Jewish identity does not need to imply religious orthodoxy. Accordingly, Jewish identity can be cultural in nature. Jewish identity can involve ties to the Jewish community. Orthodox Judaism bases Jewishness on matrilineal descent. According to Jewish law (halacha), all those born of a Jewish mother are considered Jewish, regardless of personal beliefs or level of observance of Jewish law. Progressive Judaism and Haymanot Judaism in general base Jewishness on having at least one Jewish parent, while Karaite Judaism bases Jewishness only on paternal lineage. These differences between the major Jewish movements are the source of the disagreement and debate about Who is a Jew?.
Jews who are atheists or Jews who follow other religions (Christianity etc) may have a Jewish identity. While the absolute majority of people with this identity are of Jewish ethnicity, people of a mixed Jewish and non-Jewish background or gentiles of Jewish ancestry may still have a sense of Jewish self-identity.
Jewish identity can be described as consisting of three interconnected parts:
Jewish peoplehood, an ethnic identity composed of several subdivisions that evolved in the Diaspora.
Jewish religion, observance of spiritual and ritual tenets of Judaism.
Jewish culture, celebration of traditions, secular and religious alike.
In classical antiquity, the Jewish people were constantly identified by Greek, Roman, and Jewish authors as an ethnos, one of the several ethne living in the Greco-Roman world. Van Maaren utilizes the six attributes that co-ethnics share, as identified by Hutchinson and Smith, to show why ancient Jews may be considered an ethnic group in modern terminology. Those include:
A common proper name that identifies and conveys the "essence" of its community.