Roczniki Filozoficzne

Volume 65, Issue 2, 2017

Leibniz: Personal Identity and Sameness of Substance

Leibniz’s theory of personal identity has been the object of numerous discussions and various interpretations. In the paper I contrast my view on Leibniz’s solution to the problem of personal identity with the view of Margaret Wilson and Samuel Scheffler. They both claimed that Leibniz failed to formulate a coherent, uniform and tenable theory of personal identity. His stance - as they state - contains so many inconsistencies that it cannot be adopted as a satisfactory solution to this problem. I disagree with this opinion. It is my conviction that a more inquisitive analysis of Leibniz’s texts leads to the conclusion that such severe criticism of the results of Leibniz’s studies of personal identity is ill-founded. My paper consists of two parts. In the first part— drawing on suggestions made by Vailati, Thiel, Noonan, and Bobro—I attempt to present the essential arguments against the interpretation offered by M. Wilson and S. Scheffler. In the second part I address two issues. First, I try to discuss the reasons which Leibniz listed to support his thesis that personal identity requires both the continuity of substance and the continuity of some psychological phenomena. Then, I turn to identifying Leibniz’s arguments which support the thesis that what ultimately provides a person with identity is their substantial principle, i.e. the soul or “I.”