Over the past half century, our best scientific understanding of the immune system has been transformed. The immune system has turned out to be extremely sophisticated, densely connected to the central nervous system and cognitive capacities, deeply involved in the production of behavior, and responsive to different kinds of psychosocial event. Such results have rendered the immune system part of the subject-matter of psychology and cognitive science. I argue that such results, alongside the history of psychoneuroimmunology, give us good reason to be skeptical about the characterization of cognitive science and psychology as studying the mind and the mental.