Spinoza’s Metaphisics is comprised of two parts. The first four chapters concentrate on the metaphysics of substance, while the last two address Spinoza’s metaphysics of thought. These two parts are closely connected, and several crucial claims in the last two chapters rely on arguments advanced in the first four. I intentionally use the term ‘metaphysics of thought’ rather than ‘philosophy of mind’ for two main reasons. First, the domain of thought in Spinoza is far more extensive than anything associated with human minds, as will become clear by the end of the work. Second, my primary interest in the last two chapters will be in the ontology of thought in Spinoza, rather than in the kinds of questions we associate with the philosophy of mind.
In the first chapter I study the substance-mode relation in Spinoza, and criticize Edwin Curley’s influential interpretation of the nature of this relation. Relying on a variety of texts and considerations, I establish that Spinozist modes both inhere in and are predicated of the substance. I show that Pierre Bayle’s famous critique of Spinoza’s claim that all things inhere in God is based on crucial misunderstandings. I also argue that this claim of Spinoza’s involves no category mistake, and I criticize Curley’s use of the principle of charity to motivate his reading. Finally, I discuss the similarities between Spinoza’s understanding of modes and current trope theories.