Consciousness: Confessions of a Romantic Reductionist (The MIT Press)

by Christof Koch

Functionalism applied to consciousness means that any system whose internal structure is functionally equivalent to that of the human brain possesses the same mind. If every axon, synapse, and nerve cell in my brain were replaced with wires, transistors, and electronic circuitry performing exactly the same function, my mind would remain the same. The electronic version of my brain might be clunkier and bigger, but provided that each neuronal component had a faithful silicon simulacrum, consciousness would remain. It is not the nature of the stuff that the brain is made out of that matters for mind, it is rather the organization of that stuff—the way the parts of the system are hooked up, their causal interactions. A fancier way of stating this is, “Consciousness is substrate-independent.” Functionalism serves biologists and engineers well when figuring out and mimicking nature, so why abrogate it when it comes to consciousness?