 Mach and James understand neutral monism as an especially radical form of achieving perceptual contact with the world. It might be understood as a limiting case of naïve realism—a case in which the relation between the subject and its perceptual object becomes the identity relation. In perception “subject and object merge” (James 1905: 57). A single reality—a red patch, say, when we see a tomato—is a constituent of two groups of neutral entities: the group that is the perceiver, and the group that is the tomato. The mind and its object become one. In James’s words: 