Despite his patient attempt to reconstruct Jung's metaphysics, Jon Mills fails to show that Jung was a metaphysician or even a philosopher of science and perhaps even a scientist. Mills seems to equate metaphysics with the postulation of immaterial entities - notably, archetypes. But on the one hand metaphysics can be materialist as well as dualist. On the other hand it is a speculative enterprise. A metaphysician would not simply announce the existence of immateriality but would seek to prove that immateriality fits the nature of reality as already known. Jung's metaphysics, which for him means sheer pronouncements, constitutes neither psychologism nor idealism, as Mills seems to agree. But Jung is not a Kantian, either. Jung should be treated as a great psychologist, but not as a thinker. Despite his patient attempt to reconstruct Jung's metaphysics, Jon Mills fails to show that Jung was a metaphysician or even a philosopher of science and perhaps even a scientist. Mills seems to equate metaphysics with the postulation of immaterial entities - notably, archetypes. But on the one hand metaphysics can be materialist as well as dualist. On the other hand it is a speculative enterprise. A metaphysician would not simply announce the existence of immateriality but would seek to prove that immateriality fits the nature of reality as already known. Jung's metaphysics, which for him means sheer pronouncements, constitutes neither psychologism nor idealism, as Mills seems to agree. But Jung is not a Kantian, either. Jung should be treated as a great psychologist, but not as a thinker.