“b. Private versus Public Data
Despite his monism, Russell continues to distinguish psychological and physical laws (“On Propositions,” Papers 8, p. 289), but this dualist element is mitigated by his belief that whether an experience exists in and obeys the laws of physical space is a matter of degree. Some sensations are localized in space to a very high degree, others are less so, and some aren’t at all. For example, when we have an idea of forming the word “orange” in our mouth, our throat constricts just a tiny bit as if to mouth, “orange.” In this case there exists no clear distinction between the image we have of words in the mouth and our mouth-and-lip sensations (Papers 8, p. 286). Depending on your choice of context the sensation can be labeled either mental or material.
Moreover, tactile images of words in the mouth do not violate the laws of physics when seen as material events located in the body, specifically, in the mouth or jaw. In contrast, visual images have no location in a body; for instance, the image of your friend seated in a chair is located neither in your mouth, jaw, nor anywhere else in your body. Moreover, many visual images cannot be construed as bodily sensations, as images of words can, since, no relevant physical event corresponding to the visual image occurs. His admission that visual images are always configured under psychological laws seems to commit Russell to a doctrine of mental particulars. For this reason, Russell appears not so much to adopt neutral monism, which rejects such entities, as to adapt it to his purposes.”