In his review of E. M. Macphail's The Evolution of Consciousness ("The pleasure principle and beyond", THES, October 15), Anthony Freeman brings out the point that physicalist views have great difficulty assigning any causal role to pain, as such, and he reports Macphail's conclusion that consciousness has no obvious function.
What Freeman does not say is that this can be considered a reductio ad absurdum of physicalism. On the one hand, does anyone really believe that pain is not causally efficacious? On the other, can anyone provide even the beginnings of a physicalist explanation of this efficacy?
If our cognitive processes were fully explicable as computations, then to suggest a causal role for pain would be like suggesting that to get a computer to follow its program, we should try to set it up so that it feels pain if it fails to do so.
David Hodgson
Supreme Court of New South Wales
Sydney, Australia