The question of how Jews would fit in when cultural and linguistic identity became the basis of citizenship, and the Volksgeist was embodied in a Volksstaat, could be answered in only one of two ways. Either the Jews had to surrender their Jewishness and become good Germans or there would be no place for them. At the end of the eighteenth century and the beginning of the nineteenth, a liberal assimilationist perspective was ascendant in German thought, but beneath it lurked a deep intolerance of the Jew who remained distinctive. In 1793, the philosopher Johann Gottlieb Fichte, who professed to be advocating that Jews be given "human rights," put the choice before them in starkly brutal terms: "As for giving them [the Jews] civil rights, I see no remedy [*72] but that their heads should be cut off in one night and replaced with others not containing a single Jewish idea."
George M. Fredrickson, Racism: An Introduction (Princeton: Princeton UP, 2002), 71-72.
Similar sentiments were expressed in France during this time period. And, of course, this theory of enlightenment universalism is the guiding force behind much of modern Western philosophy in America and Europe -- including the "color-blind" theory of race relations and the doctrine of strict separation between Church and State.
Notice how obliterating Jewish distinctiveness was cast as being in accordance with securing human rights -- Jews literally had to be destroyed in order to be saved. The evident Christian overtones accentuate the fact that this "liberal" revolution was hardly the break from the past that it used to be -- it merely found new language to express its fear of Jewish difference and its desire for Jews to disappear. Given that the "universal" personhood Jews were expected to assimilate into was based on a Christian norm, even the desire for conversion is barely affected. All that changed was the removal of the few protections Jews had when their oppression was strictly theological: at least some Christians theologians had some need for some living Jews -- the model expressed here explicitly wanted all Jews to disappear and pointedly chose a very violent metaphor to bring across its point.
It's no wonder that many post-Holocaust theorists consider the Shoah to be the bastard child of the Enlightenment.