 In the Critique of Pure Reason, Kant presents two distinct arguments for it. The first is a non-moral argument and is found in the B-Paralogism, after his rejection of Mendelssohn’s argument for the same. Mendelssohn’s argument builds off the thesis that the soul is a simple entity and cessation of existence involves a dissolution of one part and then another. He thus concludes that since the soul is simple, it is impossible for it to cease to exist. Kant rejects this argument on the grounds that even simple beings can have a degree of reality (an intensive magnitude) that can diminish to zero, he shortly thereafter presents his own argument for the soul’s immortality, one that has a similar metaphysical bent: (a) since throughout nature there is a proportionality between purposes and the conditions for the realization of those purposes, there should be a similar proportionality between our capacities and the conditions for their realization, and (b) since the grandeur of our capacities, including both our natural talents and moral vocation, exceeds what can be realized in this life, it follows (c) that we are justified in affirming a “future life”. This argument, or one very similar to it, is also present in the Canon’s discussion of “doctrinal belief” [doctrinale Glaube]. However, this is not an argument that endures beyond the 1780s. It is absent in later works, and in the Critique of Judgment, Kant explicitly dismisses it along with all other non-moral arguments for the afterlife (cf. AK 5:460 &amp; 5:468 [1790]).