Once linked, antisemitism and racism energized each other. But racial antisemitism could never have arisen had it not been for the nonracial forms of antisemitism that were at its roots. Although Jewish identity is ordinarily passed from parent to child, anyone, in principle, can be Jewish. Therefore, Nazi ideology to the contrary notwithstanding, racial characteristics cannot define Jews in any "essential" way. Jews have to be identified in other ways before it is possible to impute racial identity to them. Thus, behavior--what Jews do or do not do--becomes critical in defining identity prior to the imputation of racial differences. Behavior, however, is also problematic in establishing distinctively Jewish identity--at least that is true if one focuses only on the work that Jews do, the professions they practice, the economic plans or political persuasions they possess. For in and of themselves, those roles can usually be filled by all kinds of people. There is, however, at least one distinguishing and far-ranging behavioral difference.