Baruch Spinoza is often cited as a forerunner of current ideas in neuroscience and neurobiology and is seen as an early champion of embodied cognition. This article aims to specify in what way Spinoza’s ideas are useful to current research on the mind-body problem. Rather than seeking coincidences here and there between Spinoza’s positions and current findings, the article proposes that Spinoza provides a broad ontological framework that can guide research. This idea is fleshed out by contrasting Spinoza’s ideas on emotions, the treatment of harmful passions, and the mind-body relationship with those of Descartes; by showing how Spinoza’s positions are importantly different from those of current neuroscience; and by showing how Spinoza proposes a solution to the problem of consciousness that makes use of his ontological framework, which suggests an heuristic in which mind and body can be treated as hermeneutical keys to each other.