Kant on the identity of persons

According to Kant, the rationalist notion of a person as a thinking substance, conscious of its own identity through time, trades on an ambiguity concerning the meaning of 'being conscious of the numerical identity of oneself at different times'. I argue that against the rationalist notion, Kant endorses the notion of a person as a spatio-temporal entity endowed with unity of apperception and capable of knowing its own identity through time according to empirical criteria of identification and re-identification. Nevertheless, Kant maintains that the rationalist notion is both 'necessary and sufficient for practical use'. I argue that in fact, Kant's empirical notion of a person was sufficient even for the purposes of his moral philosophy. I conclude by comparing my analysis of the strengths and weaknesses of Kant's view with Peter Strawson's analysis of Kant's argument in the Paralogisms of Pure Reason.