For any materialist vision of consciousness, the crucial stumbling block is the question of free will. A modern, enlightened person tends to feel that he or she has rejected a mystical, immaterial conception of the eternal soul in exchange for a strictly scientific understanding of consciousness and selfhood—as something created by the billions of neurons in our brains with their trillions of synapses and complex chemical and electrical processes. But the fact of our being entirely material, hence subject to the laws of cause and effect, introduces the concern that our lives might be altogether determined. Is it possible that our experience of decision-making—the impression we have of making choices, indeed of having choices to make, sometimes hard ones—is entirely illusory? Is it possible that a chain of physical events in our bodies and brains must cause us to act in the way we do, whatever our experience of the process may be?
In my conversations with the philosopher Riccardo Manzotti, we have explored his Mind-Object Identity Theory, a hypothesis that shifts the physical location of consciousness away from the brain and its neurons. Rather than representations in the head, Riccardo suggests that our experience is made up of the very world we perceive. But if this is the case, if subject and object are one in experience, does this not make it all the more difficult to explain our impression of free will? Isn’t it precisely our moment-by-moment awareness of making decisions that proves that we are separate and sovereign subjects moving in a world of objects that remain quite distinct from us and over which we have an obvious mastery?