I argue for a strict identity interpretation of Spinoza's metaphysics. This interpretation is contrasted with two of leading interpretations of Spinoza on the relation between attribute and substance. In particular, the interpretations of Jonathan Bennett and Edwin Curley. I show that there are difficulties with both of these interpretations. In response I claim that the relation between attribute and substance in Spinoza is one of identity. Each attribute of a substance is in fact the essence of that substance. I argue that the essence of substance, for Spinoza, is identical to that substance. To explain why Spinoza claims that there is more than one attribute I appeal to Descartes' theory of distinctions. Attributes are only conceptually distinct from every other attributes as well as the one substance, thus each attribute refers to the same thing.