Abstract

Kris McDaniel has argued that strong composition as identity entails a principle he calls the Plural Duplication Principle, and that is inconsistent with the possibility of strongly emergent properties. Theodore Sider has objected that this possibility is only inconsistent with a closely analogous principle he calls the Set Duplication Principle. According to Sider, however, the friend of strong composition as identity is under no pressure to accept. In this paper, I argue that she has strong reason to accept either or a principle that is also inconsistent with the possibility of strongly emergent properties.