Summer’s here, so I’ll probably post less often (as, once on the web, I’m stuck here for hours, whereas it’s sunny out), but it occurs to me (halfway through Chalmers’ 1996) that I ought to say what I’ve meant by ‘dualism’ (about mind and brain). Thus far, only what I picked up from reading Descartes, so this short post won’t be cutting-edge (I’ll post a more precise statement of, and proper arguments for, my position when my relevant reading is up-to-date), but it may belatedly clarify my recent Carnival post (and better-informed readers might point me in useful directions as a result of it).
......I’d assumed that if, for example, the evolution of our brains was what caused (not only our mental complexity, but also) our individual subjectivities to arise, i.e. if we could only exist as an aspect of something physical, then even were physics not causally closed (e.g. even if subjective feelings such as pain sometimes caused personal actions) nonetheless the world would be essentially materialistic. So to begin with, I’m surprised that such beliefs (as that one) are dualistic. In Chalmers' terminology, Naturalistic dualism regards physics as causally closed, while Interactionist dualism (e.g. that belief) regards it as open. He is the former, and by his lights I’m the latter, but I see myself as a Substantial dualist, and all of Chalmers' dualisms as Superficial.
......And I don't think that Substantial dualism is opposed to my taking seriously our natural sciences. After all, these do appear to be early days for psychological theorising. Cf. how mysterious time is, for example (for all its obviousness), and how our ideas of what it might be have changed, in various ways, from Newton (and the seeming irrelevance, for our concept of time, of the shift from Ptolemaic astronomy) to Einstein (and beyond); or imagine an AI looking down on some part of America and seeing buildings and cars. It might explain its observations in terms of laws relating those two, but eventually it notices suits moving between them, and so posits that Earthlings are actually those suits. Of course, we are not alienated from our own natures, so we might (even at this dawn of our psychologies) know enough about ourselves to see the prima facie implausibility of all the Superficial dualisms of Chalmers’ 1996.
......For Chalmers (1996: 157-8), Interactionist dualism is no less epiphenomenalistic than Naturalistic dualism: “We can always subtract the phenomenal component from any explanatory account, yielding a purely causal component.” But suppose that minds do sometimes communicate directly (the evidence being currently inconclusive). The non-physicality of the medium might be indicated by the independence of the telepathic correlations from the physical separations of the subjects, for example, but furthermore its non-existence might follow from metaphysical considerations. An explanatory account of such telepathy might appeal to simple psychical laws (e.g. those of a fictional medium, cf. relativity physics with relational space-time) posited to explain all sorts of observed regularities, and if we were to subtract from that the awareness of thoughts we would be left with fatal gaps (in the causal chain that best explained our observations).
......(PS, added July 2) Well, that was a wet month after all. Anyway, it occurs to me to note that even a Substantial dualism (i.e. one that is not epiphenomenalistic, one in which mind does not supervene upon brain) need not be commited to an implausible substance dualism (since that depends upon what is meant by 'substance'). If mind does not supervene upon, does not arise from matter, then it is not so implausible that there is a Creator, that both mind and matter are alike in being divine creations, which would naturally interact (cf. how plausible it is that a metal ball dropped upon a wooden floor, or a sandy beach, should interact with it, should leave a round indentation upon that other material, just because they have so many properties in common, notably a common origin).