Persistence: a matter of identity?

How do objects persist? What does it mean to persist? We do perhaps all have an intuitive understanding of what it means for an object to persist. An answer like “an object that persists exists both in the past and the future” or “a persisting object lasts for a period of time” might immediately come to mind. But the details of persistence become more obscure when we dive into a closer study of persistence and its connected concepts. How can an object that persists through a change of properties be the same identical object before and after this change? Change implies that the object has different properties at different times, which seems to be inconsistent with the concept of identity. In this essay, I will explore the apparent problems with combining persistence with identity and change. The essay will examine solutions from the doctrines of three dimensionalism and four dimensionalism. My main focus is on the latter doctrine, and specifically on David Lewis’ version called perdurantism¸ and Theodore Sider’s version called the stage theory. Sider introduces a rather unorthodox view of persistence which employs a temporal counterpart theory to analyse persistence statements. This theory will be extensively explored and discussed. My claim is that this analysis, though it is unorthodox, is still the best understanding of how things persist. However, its details are not fully accounted for by Sider, and I will propose some adjustments