Microstructure without essentialism: A new perspective on chemical classification

Recently, macroscopic accounts of chemical kind individuation have been proposed as alternatives to the microstructural essentialist account advocated by Kripke, Putnam, and others. These accounts argue that individuation of chemical kinds is based on macro-scopic criteria such as reactivity or thermodynamics, and they challenge the essentialism that grounds the Kripke-Putnam view. Using a variety of chemical examples, I argue that microstructure grounds these macroscopic accounts, but that this grounding need not imply essentialism. Instead, kinds are individuated on the basis of similarity of reactivity between substances, and microstructure explains similarity of reactivity.