In the middle of the 18th century in Germany was the unique religious situation when within the limits of the state many different religions coexisted. It gave an impulse for German philosophers to concern the questions of religion politic and the conditions under which the harmonic coexistence of adherents of different religions within the limits of one state might be possible. The article considers two such projects - the project of Kant (presented above all in a later work "Religion within the Limits of Reason Alone" and in an earlier article "An Answer to the Question: What is Enlightenment?") and the project of Mendelssohn (in the work "Jerusalem or on Religious Power and Judaism"). The positions of both philosophers have very many common features, what allows us to assume a certain influence of Mendelssohn if not on the origin of the ethic-religious views of Kant then at least on the direction Kant's views developed and on the form they were expressed.