This essay will explain the philosophical theory known as nonreductive materialism. It will then identify the problems that this theory encounters with respect to causation and then, given its admission of an irreducibly mental aspect of the brain or body, substance dualism seems to threaten. Ideas advanced by Searle, Kim, Nagel, Swineburn, Willard and others will be incorporated into this analysis, which will argue that the prospects for substance dualism (in the Cartesian sense) are limited at best.
John Searle (277) states that "mental phenomena are caused by neurophysiological processes in the brain and are themselves features of the brain." This represents the fundamental basis of a nonreductive materialism in which a natural phenomena is identified by Searle (279) as linking the mental and the physical realm in nature and positing that the mental and the physical are the same in kind, therefore rejecting Cartesian dualism and positing a unity between the physical and the mental.
This particular view is affirmed in part by J.J. Smart (20-21) who maintains that a lack of awareness in consciousness of our experiences as physical or neurological processes leads us to think that we are aware of them as nonphysical. In other words, knowledge of the neural and neutral properties of physical processes gained through science, observation, and new technologies invariably leads to the belief that it is ultimately impossible to differentiate between two different substances (i.e., the mind and the body). This particular approach reduces in fact to property dualism which encompasses the awareness of the categories of knowledge or action in which materialism becomes what Searle (296) calls "the finest flower of dualism."
Kim (242) describes nonreductive materialism as emerging from the fact that reductionism in the mind-body problem has been out of fashion since the 1960s and a desire to achieve true physicalist expla...