Neutral monism  In the philosophy of mind, neutral monism is the view that the mental and the physical are two ways of organizing or describing the same elements, which are themselves "neutral", that is, neither physical nor mental. This view denies that the mental and the physical are two fundamentally different things. Rather, neutral monism claims the universe consists of only one kind of stuff, in the form of neutral elements that are in themselves neither mental nor physical. Neutral monism about the mind–body relationship is described by C. D. Broad in one of his earlier works, "The Mind and Its Place in Nature". Broad's list of possible views about the mind-body problem, which became known simply as "Broad's famous list of 1925" (see chapter XIV of Broad's book, ) states the basis of what this theory had been and was to become. Some examples of philosophers who are seen to have a neutral monist view are Baruch Spinoza, David Hume, Roberto Ardigò, Ernst Mach, Richard Avenarius, Kenneth Sayre, Joseph Petzoldt and Jonathan Westphal. There are few self-proclaimed neutral monists. Most who are regarded as of this view were classified as such after their deaths. Earlier, William James had propounded the notion in his essay "Does Consciousness Exist?" in 1904 (reprinted in "Essays in Radical Empiricism" in 1912). Whately Carington in his book "Matter, Mind, and Meaning" (1949) advocated a form of neutral monism. He held that mind and matter both consist of the same kind of components known as "cognita" or sense data. Russian psychologist Boris Sidis also appears to have adhered to some form of neutral monism. According to Stephen Stich and Ted Warfield, neutral monism has not been a popular view in philosophy as it is difficult to develop or understand the nature of the neutral elements. In 1921, Bertrand Russell adopted a similar position to that of William James. Russell quotes from James's essay "Does 'consciousness' exist?" as follows:  Russell summarizes this notion as follows:  Russell observes that the same view of "consciousness" is set forth in James's succeeding essay, "A World of Pure Experience" ("ib.", pp. 39–91). In addition to the role of James, Russell observes the role of two American Realists:  Russell goes on to agree with James and in part with the "American realists":   David Chalmers considers the consciousness of rocks as well as thermostats, although he eschews the notion that rocks are conscious: In his 2002 "Consciousness and its Place in Nature", Chalmers carefully considers neutral monism and panpsychism, variants of what he calls "Type-F Monism".