The knowledge argument is generally supposed, if successful, to show that physicalism cannot accommodate certain conscious mental states. For the rest of the natural world, it is fine. What the argument actually shows is that physicalism cannot accommodate the qualitative aspects of reality, and without these the world is purely abstract, formal or mathematical entity. Given a minimal transparency in experience, our manifest world is a projection of the nature of our qualia, and without this manifest world, we could not have a scientific conception. Traditional empiricism recognizes the foundational role played by the qualitative nature of experience.in the constitution of our conception of the world. Physicalist metaphysics pretends we have an autonomous scientific conception of the physical, which can then swallow up the qualitative nature of experience. Traditional empiricism is demonstrably in the right on this matter.