 But traditional neutral monism provides an ontology rich enough to address this problem. The pink shape experienced by the drunkard exists: it is a portion of pure experience (James), or an element (Mach). This much naïve realism is true, even in the cases of nonveridical experience. But the pink rat that the drunkard takes himself to see does not exist—the pink patch he sees is not a member of a group of neutral elements that constitute a rat. There is nothing wrong with the drunkard’s visual experience; what is mistaken is his assumption that what he sees is a rat. Russell (though not a naïve realist himself) states this point most succinctly: “There are in fact no illusions of the senses, but only mistakes in interpreting sensational data as signs of things other than themselves” (Russell 1948: 149–50). Mach puts the point as follows: 