Parallel Computation and the Mind-Body Problem

The position in the philosophy of mind called functionalism claims that mental states are to be understood in terms of their functional relationships to other mental states, not in terms of their material instantiation in any particular kind of hardware. But the argument that material instantiation is irrelevant to functional relationships is computationally naive. This paper uses recent work on parallel computation to argue that software and hardware are much more intertwined than the functionalists allow. Parallelism offers qualitative as well as quantitative advantages, leading to different styles of programming as well as increased speed. Hence hardware may well matter to the mental: only by further empirical investigations of the relation between the mind and brain and between artificial intelligence software and underlying hardware will we be able to achieve a defensible solution to the mind-body problem. The major disadvantage of parallel systems is the need to coordinate their subprocesses, but recent proposals that consciousness provides a serial control for parallel computation are implausible.