INTRODUCTION

When David Chalmers introduced the notion of the “hard problem of consciousness” (1995), he contributed to a revolution in the neuroscience of consciousness and cognition as well as in the philosophy of mind. The main point of the hard problem is that, even if we could discover the “neural correlates of consciousness,” we still would not have answered the “harder” question: Why do those physical events exhibit the property of consciousness, whereas other physical events do not?

I acknowledge that this “hard problem” notion should not be construed as an argument for mind-body dualism, or as a reason to reject physicalism. (More on that later.) None the less, Chalmers' point has important implications for neuroscience in general, as well as cognitive science in particular. There is a tendency in neuroscience to assume that if a brain process B correlates with a mental process M, then B is the physical process that produces M. But this reasoning can lead to gross oversimplifications. There may be a much more complicated process, P, that causes both B and M to occur, and therefore causes B and M to correlate with each other. To be sure, P may very well be a purely physical process. My point is that P often may be a more complicated physical process than just B. In some cases, it may turn out that B is actually a somewhat minor or even peripheral part of the more complicated process P that causes B and M to correlate.