The second point in Dohm's memoir which did not please Mendelssohn was, that it demanded the recognition of the state for the Jewish religion, inasmuch as the government was to grant it the right of excluding unruly members by a sort of excommunication. This did not harmonize with his conception of a pure religion. In order to counteract the errors of Dohm's well-meant apology, and the obstinate misapprehension of the Jews as much as possible, Mendelssohn caused one of his young friends, the physician Marcus Herz, to translate from the English original the "Vindiciæ Judæorum" of Manasseh ben Israel against the numerous slanderous charges brought against them. He himself wrote a preface full of luminous, glowing thoughts (March, 1782), called "The Salvation of the Jews," as an appendix to Dohm's work. Manasseh's Apology was buried in a book little read; Mendelssohn made its excellent truths known among the cultured classes, and by a correct elucidation gave them proper emphasis. In this preface he insisted, that while the church arrogates the right of inflicting punishment upon its followers, religion, the true faith, based upon reason and love of humanity, "requires neither an arm nor a finger for its purpose; it concerns only the spirit and the heart. Moreover it does not drive sinners and renegades from its doors." Without knowing the whole extent of the harm caused by it in the course of Jewish history, Mendelssohn detested the interdicting power. He therefore adjured the rabbis and elders to give up their right of excommunicating.
"Alas! my brethren, you have felt the oppressive yoke of intolerance only too severely; all the nations of the earth seem hitherto to have been deluded by the idea that religion can be maintained only by an iron hand. You, perhaps, have suffered yourselves to be misled into thinking the same. Oh, my brethren, follow the example of love, as you have till now followed that of hatred!"
Mendelssohn now held so high a position in public opinion, that every new publication bearing his name was eagerly read. The fundamental thought of the preface to Manasseh ben Israel's "Vindication," that religion has no rights over its followers and must not resort to compulsory measures, struck its readers with astonishment. This had never occurred to any Christian believer. Enlightened Christian clergymen, such as Teller, Spalding, Zollikofer, and others, gradually fell in with the new idea, and tendered its originator public applause. Bigoted clerics and obdurate minds, on the other hand, beheld therein the destruction of religion. "All this is new and difficult; first principles are denied," said they. In Jewish circles also many objections were made to Mendelssohn's view. It seemed as if he had suddenly discarded Judaism, which certainly owns an elaborate system of penalties for religious crimes and transgressions. From the Christian camp a pamphlet called "Inquiry into Light and Truth" was launched against him, which asserted that he had finally dropped his mask; that he had embraced the religion of love, and turned his back upon his native faith, which execrates and punishes.