Consciousness and its Place in Nature

Consciousness fits uneasily into our conception of the natural world. On the most common conception of nature, the natural world is the physical world. But on the most common conception of consciousness, it is not easy to see how it could be part of the physical world. So it seems that to find a place for consciousness within the natural order, we must either revise our conception of consciousness, or revise our conception of nature. In twentieth-century philosophy, this dilemma is posed most acutely in C. D. Broad’s The Mind and its Place in Nature (Broad 1925). The phenomena of mind, for Broad, are the phenomena of consciousness. The central problem is that of locating mind with respect to the physical world. Broad’s exhaustive discussion of the problem culminates in a taxonomy of seventeen different views of the mental-physical relation.2 On Broad’s taxonomy, a view might see the mental as nonexistent (“delusive”), as reducible, as emergent, or as a basic property of a substance (a “differentiating” attribute). The physical might be seen in one of the same four ways. So a fourby-four matrix of views results. (The seventeenth entry arises from Broad’s division of the substance/substance view according to whether one substance or two is involved.) At the end, three views are left standing: those on which mentality is an emergent characteristic of either a physical substance or a neutral substance, where in the latter case, the physical might be either emergent or delusive. 1Published in S. Stich & T. Warfield, eds, Blackwell Guide to Philosophy of Mind (Blackwell, 2003). This paper is an overview of issues concerning the metaphysics of consciousness. Much of the discussion in this paper (especially the first part) recapitulates discussion in Chalmers (1995; 1996; 1997), although it often takes a different form, and sometimes goes beyond the discussion there. I give a more detailed treatment of many of the issues discussed here in the works cited in the bibliography. 2The taxonomy is in the final chapter, Chapter 14, of Broad’s book (set out on pp. 607-11, and discussed until p. 650). The dramatization of Broad’s taxonomy as a 4x4 matrix is illustrated on Andrew Chrucky’s website devoted to Broad, at http://www.ditext.com/broad/mpn14.html#t.