Searle on Humphrey

Philosopher of mind John Searle has written a review of Nick Humphrey's new book, "Seeing Red: A Study in Consciousness."

He doesn't much care for the book's hypothesis about the nature of consciousness, which involves the idea that sensation (roughly, qualia by another name) is separate and parallel to perception.

In a word toward explaining the quote below, the review uses a recurrent metaphor throughout. Searle proposes that Humphrey has attempted to set mind and brain equal to each other, in the form of an equation. But like any equality in physical science, this exercise requires that the measurement units be made the same on both sides of the equation. In Searle's view, this is where the book is misguided -- Searle claims that we should be looking for not an equality of mind and brain, but instead a causal account of how the physical brain gives rise to mind.

The problem with the equation mode of thinking:

The enterprise was bound to fail because the equation does not solve the problem; it presupposes that the problem has already been solved. The problem is to explain the relation of consciousness to brain processes, specifically to explain how brain processes cause (give rise to, produce, bring about) qualitative subjectivity. We already have qualitative subjectivity on the left-hand, mind, side of the equation, by definition. The question then is: How does it get into the right-hand or brain side? But that is precisely the mind-body problem, the problem that the equation was supposed to solve. Humphrey does not address that question directly; rather, he changes the subject. Our question is: How do objective third-person brain processes right here and now (as well as in earlier evolutionary times) cause our conscious states? What specific parts of brain anatomy do it and how do they work? His question is: Assuming that perception is unconscious, how might conscious sensations have evolved and what functions would they perform? His answer, in brief summary, is that they evolved by monitoring our responses to input stimuli and they function to give us a sense of "the Self." I think he is wrong to separate perception from consciousness; all the same, some evolutionary story about consciousness must be right. But whatever evolutionary story may be proposed is an answer to a different question from the causal question. The only part of his account that even hints at an answer to the causal question is the discussion of feedback mechanisms. But he does not tell us how we get from the feedback mechanisms to qualitative subjectivity.

I italicized the first sentence here because it strikes me as very useful -- one could for example make the same observation about Daniel Dennett's "Cartesian theater" account of consciousness. The problem is that if your theory asserts that the "problem" of mind is not really a problem, because mind just is some aspect of brain physiology, then you really are just presupposing that the problem has already been solved, rather than actually proposing some solution.

Searle is, as he often has been, a persuasive proponent of the idea that consciousness remains to be explained.