In this paper, I argue that Spinoza holds a perspectivalist view of mereological composition, a form of anti-realism. The paper has two parts: In the first half of the paper, I introduce interpretive puzzles for the standard realist reading of Spinoza’s mereology. In the second half of the paper, I discuss Spinoza’s positive view on mereological composition and present a perspectivalist reading that avoids the interpretive puzzles.