Kant's first analogy can be shown to rest on an account of the conditions under which alone we can so much as believe that there has been a case of coming to exist or ceasing to exist. The account in question is revolutionary in nature but largely unexplained. Its revolutionary nature is due to the role it ascribes to judgmental activity, and thus to the self, in the generation of an absolutely basic and ubiquitous feature of what is commonly and naturally referred to as experience. This paper will explain and defend that account, explore its role in the proof of the first analogy, and consider possible objections to other parts of that proof. The positive result should be a clear picture of one crucial role ascribed by Kant to the self and thus one major aspect of his account of human personhood.