Locke discloses the novel concept of modern subject, which is based on the episodic memory of the individuals by differentiating himself from Descartes, who lays a ground for modern universal subject in the realm of rationalism. He deals with the concept of the self-identity of person in depth in order to establish this concept of modern subject. For Locke, the personal identity is formed in succession of experience in time, whereas for Descartes, it refers to the identity of logical thinking. Thus in the theory of the identity of person or thinking subject, Descartes does not take the concept of memory into consideration, but Locke conceives the memory as a pivotal concept. In this respect, we can say that for Locke, the personal identity of the individual is grounded by his or her own experience and memory. Owing to this theory, he lays a ground for the theoretical foundation of the modern liberalistic concept of the individual. It should be, however, worth noting that Locke prepares the justification of the property right of the life, body, and the estate of modern individuals on the basis of the personal identity, which is formed by memory. It shows that for him the personal identity is presupposed also in the practical and forensic realm. Moreover, the property right of the individual is acquired only not in the state of nature, but in the political society, i.e., civil society, so that the self-identical person is conceived of as the person, who is regarded as the citizen in modern civil society. In this respect we should take into consideration that Locke established the necessary connection between the freedom, property, consent, compact, and finally the political power of modern individuals in his theoretical and practical philosophy.