A major debate among medieval rabbis concerns the question of whether the Torah commands belief in God. To many, the opening words of the Ten Commandments, “I am the Lord your God . . . ,” constitute just such an injunction; to others, these are simply a preamble. The 18th-century Jewish philosopher Moses Mendelssohn favored the latter view. Drawing on both Mendelssohn’s primary treatise on Judaism, Jerusalem, and on his less-studied commentary on the Torah, Judah Kerbel explains how this opinion reflects his interpretation of revelation itself:
Mendelssohn does not believe that the goal of revelation is to prove God’s existence. A miraculous feat does not prove God’s existence for the current non-believer. . . . Instead, to reach belief in God, one needs to hold a received tradition of God’s existence, to determine this truth independently, or to learn the existence of God from other reliable people, be they older family members or scholars. . . . [O]nly those who already believe in God experience revelation as divine, and that experience requires prior learning by some means or another. . . . Mendelssohn claims that the main purpose of the first statement [of the Decalogue] is “to single out [the children of Israel] as a treasure from all the peoples.” . . .
On the contrary, supernatural proofs of God’s existence, as Mendelssohn writes in his commentary on Exodus, are unpersuasive. Rather, we achieve an understanding of God through the intellect. . . .
Mendelssohn [thus believes] that anyone who was present at revelation may have experienced wonder of some sort at the natural sights, but this would not have convinced anyone of anything new or life-altering unless [belief] “was, perhaps, taught, explained, and placed beyond all doubt by human reasoning” [beforehand]. Mendelssohn explains the verse “I am the Lord” as a historical foundation for the commandments but not as a new truth. . . .
This approach to revelation also informs Mendelssohn’s view of other religions. Since God’s existence is discerned through the intellect, and revelation at Sinai does not serve the purpose of proving this point, Mendelssohn affirms the validity of other religions (although it is fascinating that he strongly condemns atheism, calling it an illness that makes society “sick and miserable, whether it is worn down by cancer or consumed by fever”).
Thus, writes Kerbel, Mendelssohn was able to justify, through his philosophy of revelation, both his devotion to the idea of Jewish chosenness and his radical commitment to tolerance.