Unsurprisingly, then, Spinoza has not solved the mind-body problem. But he has advanced our understanding of it. He has shown how, if one skillfully and consistently wields the PSR and the conceptual barrier between thought and extension, one can construct an argument for the view that there is one substance and one can undermine the Cartesian intuitions that material things and physical things cannot be identical.

Spinoza (2008) - Two: The Metaphysics of Substance