The physicalist conception of the soul as being supervenient upon neurochemical processes in the brain entails certain logical consequences that place it in direct opposition to the Scriptural teaching regarding man’s salvation. What follows will be a brief enumeration of the logical consequences of a physicalist conception of the soul of man, and a demonstration of how they are in direct opposition to the Scriptural teaching regarding man’s salvation.
If the soul is a byproduct of the body, then changes to the body necessarily entail changes to the soul. Thus, for every positive or negative bodily change there is a corresponding positive or negative soul change. Bodily health, for instance, would correspond to soul health, whereas bodily illness would correspond to soul illness. Similarly, bodily simplicity or complexity would be correlative to the soul states produced by the body. The soul of an infant would correspond to the level of simplicity of the body which has produced it. Inversely, the soul of an elderly man would correspond to the level of complexity of the body which has produced it. For every bodily change, therefore, there is a necessary soul change corresponding to the body which has produced it.
Since the fall of man, humanity has been cursed with bodily weakness, illness, decay, and death. Man also, of course, is born spiritually corrupt, ill, decaying, dead. Thus far, the correlative states of body and soul seem to find corroboration in Scripture. This is not the case, however, for God regenerates sinners. Scripture teaches that man is given a new heart, i.e. a renewed soul that struggles against sin, moral corruption, and spiritual illness. That is not all that occurs in the heart of man, either; man’s mind is renewed by the Scriptures and the Holy Spirit. This all occurs in man’s heart/soul, moreover, in spite of the fact that man’s body is gradually failing. Bodily decay and death, according to the Scriptures, will not be eradicated until Christ returns.
Yet if the body and soul are necessarily qualitatively correlative to one another, Christian sanctification must correspond to changes in the body of the believer. Wouldn’t this imply that the believer would not die but perpetually exist in tension between life and death? If physicalism is true, to ask the question more forcefully, then why do any Christians even get sick? Wouldn’t Job’s friends be vindicated by such a doctrine, seeing as they attribute Job’s bodily suffering to his sin? The answer seems to be “Yes.”
Thus, if the soul is supervenient upon the body, and bodily states are qualitatively correlative to soul states, and soul states include (a.)being unregenerate, (b.)being regenerate, and (c.)being regenerate and undergoing the processes of sanctification, then (a.), (b.), and (c.) must each have qualitatively correlative bodily states. However, the unregenerate are sometimes physically superior to the regenerate. Likewise, the regenerate are, many times, weaker than the unregenerate. Thus, physicalism cannot be true, for (a.), (b.), and (c.) do not have qualitatively correlative bodily states.