In this paper, I suggest an outline of a new interpretation of core issues in Spinoza’s metaphysics and philosophy of mind. I argue for three major theses. (1) In the first part of the paper I show that the celebrated Spinozistic doctrine commonly termed “the doctrine of parallelism” is in fact a confusion of two separate and independent doctrines of parallelism. Hence, I argue that our current understanding of Spinoza’s metaphysics and philosophy of mind is fundamentally flawed. (2) The clarification (...) and setting apart of the two doctrines will also put us in a position to present my second major thesis and address one of the more interesting and enduring problems in Spinoza’s metaphysics: how can the attribute of thought be, on the one hand, isomorphic with any other attribute, and yet, on the other hand, be isomorphic with God himself, who has infinitely many attributes? In the second part of the paper, I present Spinoza’s solution to this problem. I argue that the number and order of modes is the same in all attributes. Yet, modes of Thought, unlike modes of any other attribute, have an infinitely-faceted internal structure so that one and the same idea represents infinitely many modes by having infinitely many facets (or aspects). (3) This new understanding of the inner structure of ideas in Spinoza will lead us to my third thesis in which I explain and solve another old riddle in Spinoza’s metaphysics: his insistence on the impossibility of the human mind knowing any of God’s infinite attributes other than Thought and Extension. In the third part, I show some of the major ramifications of my new interpretation and respond to some important objections. In my conclusion I discuss the philosophical importance of my interpretation. I explain why Spinoza could not embrace reductive idealism in spite of the preeminence he grants to the attribute of Thought. I argue that Spinoza is a dualist -- not a mind-body dualist, as he is commonly conceived to be, but rather a dualist of Thought and Being. Finally, I suggest that Spinoza’s position on the mind-body issue breaks with the traditional categories and ways of addressing the subject by suggesting a view which grants clear primacy to Thought without accepting any idealist reduction of bodies to thought. (shrink)