Abstract

Spinoza claims that a person's body can be numerically identical over time, despite changes in its size, shape, and speed. This chapter argues that he would reject the Indiscernibility of Identicals. The Indiscernibility of Identicals is often taken to have profound implications for one's view of change. Spinoza seems to deny the existence of times, because he similarly classifies them as “beings of reason”. As Spinoza understands instantiation, whenever a property is instantiated by an object, it metaphysically depends on that object. As Spinoza understands instantiation, the existence of a property causally depends on whatever instantiates it. Spinoza says that the mind, and therefore the body, can “undergo great changes, and pass to a greater, to a lesser perfection”. Spinoza is committed to saying that all bodies are capable of change, even the shortest‐lived. Spinoza can deny that the non‐identity of Downstairs Peter and Upstairs Peter is due to their conflicting properties.