Judaism can be thought of as being simultaneously a religion, a nationality and a culture.
Throughout the middle ages and into the
20th century, most of the European world
agreed that Jews constituted a distinct
nation. This concept of nation does not
require that a nation have either a territory
nor a government, but rather, it identifies,
as a nation any distinct group of people
with a common language and culture. Only
in the 19th century did it become common
to assume that each nation should have
its own distinct government; this is the
political philosophy of nationalism. In
fact, Jews had a remarkable degree of self-government
until the 19th century. So long as Jews
lived in their ghettos, they were allowed
to collect their own taxes, run their own
courts, and otherwise behave as citizens
of a landless and distinctly second-class
Of course, Judaism is a religion, and
it is this religion that forms the central
element of the Jewish culture that binds
Jews together as a nation. It is the religion
that defines foods as being kosher and
non-kosher, and this underlies Jewish cuisine.
It is the religion that sets the calendar of Jewish feast and fast days, and it is
the religion that has preserved the Hebrew language.
Is Judaism an ethnicity? In short, not
any more. Although Judaism arose out of
a single ethnicity in the Middle East,
there have always been conversions into
and out of the religion. Thus, there are
those who may have been ethnically part
of the original group who are no longer
part of Judaism, and those of other ethnic
groups who have converted into Judaism.
If you are referring to a nation in the
sense of race, Judaism is not a nation.
People are free to convert into Judaism;
once converted, they are considered the
same as if they were born Jewish. This
is not true for a race.