This passage from Levinas outlines some important principles about the ideal relationship between politics and religion and the necessity of a secular state.

The Talmud recognizes situations that cannot be governed by the messianic principles of the future, precisely because war remains a present reality. This must be carefully considered: a situation where public liberty gives freedom to the enemies of liberty cannot be neglected under the pretext that liberty will triumph in the last analysis. Faith in the final triumph of Goodness cannot dispense men from concern and action. … Thus, absolute legislation encounters the concept of history.

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The originality of Judaism lies in placing political power next to the power of absolute morality, without limiting (contrary to Christianity) moral power to man’s supernatural destiny, without subordinating (contrary to Hegel) moral power to political power as a concrete one. But this political power maintains a certain independence. It is secular. The prince becomes the principle of law. [Or,] “the law of the state is the law.” [The prince] institutes this state as broadly independent of both ritual and moral law.

Royal and political power are separate from ritual authorities … Similarly, royal power is distinguished from the moral absolute … The philosopher-king is an absolute position; in history the king is distinguished from the philosopher.

The fact remains that the law of the Torah stands above the secular law determined by history, an order that includes the possibility of crime and war; once the political authority is called on to leave to Caesar that which belongs to Caesar, the law of the absolute does not disappear. The law of the Torah alone names, invests, and controls political power. In the name of the absolute, Absolute law is given leave of absence. “A letter may be torn out of the Torah as long as the Torah as a whole is not forgotten.”

The times of the Messiah must one day emerge from this temporal order. The political world must remain the parent of this ideal world. The talmudic apologue is particularly suggestive here. King David makes war and governs in the daytime; when men rest, he devotes himself to the law. A double life to restore the unity of life.

Of course, the problem of political authority that claims legitimacy from religion was present as early as the first Hebrew states. The Northern Kingdom of Israel fell precisely because it abused the legitimacy that G-d gave it. But outside the Tanakh, the relationship of politcs to religion is hardly a problem of Jewish leaders claiming legitimacy(at least after the Bar Kochba rebellion and the fall of the Khazars.) For the most part, Jewish politics have been predicated on relations with monarchs who derive their authority from other religions — Orthodox, Catholic, Muslim, and Protestant. They relied on the monarch’s good faith that he would not pursue conversion, and instead see the Jews as a corporate entity whose protection was somehow mandated by religious law. To be skeptical, there is something of the French Jew’s love for the republic in Levinas’ outlook. Nevertheless, Levinas casts effective doubt on the direct injection of religion into the affairs of state.