John Searle - Reductionism and the Irreducibility of Consciousness (1992)

So far in this festive season of emergence, we have seen the radically strong position (i.e., emergent properties are real and ontologically irreducible to their parts); and the radically weak position (i.e., emergent properties are illusory, a consequence of our present ignorance of their true causal factors). With Searle's Reductionism and the Irreducibility of Consciousness, we start hitting the nitty-gritty, philosophically refining the space between these two polar points. We do so by walking into the minefield of philosophy of mind.

Consciousness is perhaps the paradigmatic example of a radically emergent phenomenon. By its nature, it is intrinsically subjective and complex (see Nagel's What Is It Like To Be A Bat?). Science is faring little better - no neurophysiological correlate has yet been found to allow us to predict reliably whether a subject is experiencing consciousness.

Searle's account begins with the claim that consciousness is emergent not just from the spatial relationships between the mind's constituent neurons, but from the causal interactions between them. He accepts that mental features (those of experience) are caused by their neural substrate, but denies that they can simply be ontologically reduced to them, in the same way that the liquidity of a substance cannot be reduced to the spatial configuration of its molecules; instead, both rely on "causal" emergence, in which the causal powers of consciousness can be fully explained by the causal powers of its underlying neurons.

Here, linguistic concepts are added to the mix, as Searle looks at how emergent concepts are formalised. Take the example of "redness". Starting with a subjective experience of red things in the world, we advance our scientific knowledge and come to the understanding that "redness" is caused by the reflection of a certain range of wavelengths of light. We then redefine "redness" as this objective, underlying principle, and our subjective experience of red things becomes relative to this real-world fact. In Searle's terminology, we "carve off the surface features" of redness - the surplus contained within a subjective experience - and are left with a relationship between affect and reality.

He proceeds to argue that, given that consciousness is itself the "subjectiveness" of experience, there is nothing to carve off, and no underlying reference point. We can no longer distinguish between the referent and our experience of it - indeed, the underlying phenomena in question is subjectivity itself. So, the two have converged, meaning that this technique of "reduction" cannot apply to consciousness, by definition.

This is all fine. However, I can't help but feel a little short-changed: all we are left with is the outcome of a metaphysical game.

Searle uses the convergence exercise to argue that "consciousness" is an irreducible fact, after whose application "we are still left with a universe that contains an irreducibly subjective physical component as a component of physical reality". That is, consciousness exists, and we cannot use the carving-off technique to attach it to some external pattern. But, in the neural state space, is it not possible that there is some continuous subspace which directly correlates to the experience of X conscious state? If so, would it not be acceptable to come to refer to this fuzzy state space as "consciousness"?

I'm away tomorrow and over the weekend, so normal advent programming will resume on Monday. Apologies for any distress this may cause.