The Jewish tradition has two distinct tendencies: the more fundamental one, represented by the philosophers and poets and scholars who were interested only in Jewish issues and in the Jewish Weltanschauung; and the other tendency associated with great figures such as Spinoza or Einstein, and to a certain extent also Heinrich Heine, and which applied the traditions of Jewish thinking to other cultures, including German culture, and to other issues. It is not difficult to see how a double identity developed among Jews.