 The most frequent type of objection to the traditional versions of neutral monism is that they are all forms of mentalistic monism: Berkleyan idealism, panpsychism, or phenomenalism. The argument is simple: sensations (Mach), pure experience (James) and sensations/percepts (Russell) are paradigms of non-neutral, mental entities. Hence there is nothing neutral about these versions of neutral monism. The prima facie plausibility of this objection is beyond doubt. But it is also clear that Mach, James, and Russell were acutely aware of the problem and took themselves to have responded in a satisfactory manner. They reject the view that a sensation or an experience consists of a subject directing a mental act—awareness, consciousness, acquaintance—onto on an object. Dispensing with the subject and the act, they are left with what used to be the object—a red patch, say. And they hold that there is nothing mental about red patches. All it takes for this red patch to turn into a red-sensation is for it to be appropriately related to other entities of the same kind. There is no quick way to adjudicate this dispute. A careful assessment of each case is required. This type of objection—the “mentalism suspicion”—has been articulated by a diverse group of philosophers, among them: (Lenin 1909: 34; Stace 1946; Ayer 1971; Feigl 1958: 426, 1975: 26–7; Maxwell 1976: 354; Popper &amp; Eccles 1977: 199; Strawson 1994: 97; Chalmers 1996: 155; Tully 2003: 355, 369).