 As already noted, the most famous and perhaps most influential version of a moral argument for belief in God is found in Immanuel Kant (1788). Kant himself insisted that his argument was not a theoretical argument, but an argument grounded in practical reason. The conclusion of the argument is not “God exists” or “God probably exists” but “I (as a rational, moral agent) ought to believe that God exists.” We shall, however, see that there are some reasons to doubt that practical arguments can be neatly separated from theoretical arguments.