The dismissal of substance and being in Peirce's regenerated logic

After introducing the debate between substance philosophy and process philosophy, and clarifying the relevance of the category of 'substance' in Peirce's thought, the present paper reconstructs the role of 'substance' and 'being' from Peirce's early works to his theory of the proposition, provided after his studies on the logic of relatives. If those two categories apparently disappear in Peirce's writings from the mid-1890s onwards, the account of 'subject' and 'copula' in Peirce's analysis of the proposition allows one to grasp the reasons why Peirce omits 'substance' and 'being' in favor of his three categories (Firstness, Secondness, Third new), and to understand why his philosophy cannot be considered as a substance philosophy.