Q: Maybe I'm naive but it seems kind of obvious that the brain is the mechanism that -- in the context of a person's life and environment -- gives rise to consciousness. That's not to say it is the same as consciousness, but that it is the mechanism from which consciousness emerges.
Noe: The brain is necessary for consciousness. Of course! Just as an engine is necessary in a car. But an engine doesn't "give rise" to driving; driving isn't something that happens inside the engine. The engine contributes to the car's ability to drive. Consciousness is more like driving than our philosophical tradition leads us to expect. To be conscious is to have a world. The fact is, you and I don't have what it takes to make a world on our own. We find the world, we don't make it in our brains.
The brain is essential for our lives, physiology, health and experience. But the idea that it is the whole story, or even the key to understanding the story, is not a scientific conclusion. It's a prejudice. Consciousness requires the joint operation of the brain, the body and the world.
In fact, neuroscience is probably not in the best position to answer questions of consciousness and mind and experience. When we look for who and what we are in the brain alone, we lose the phenomena that interest us most.
Imagine that we find the Holy Grail of neurobiology, the patterns of neural activation that correlate perfectly with different events in our mental lives. We would still never understand or make sense of why those correlations exist. There is no intrinsic relationship between the experience and the neural substrates of the experience. We always need to look at what factors bring the two together. The environment, other people, our needs and desires -- all these things exist outside the brain and have to be seen as essential parts of our selves and consciousness. So we aren't just our brains, we're not locked inside our craniums; we extend beyond our skulls, beyond our skin, into the world we occupy.
Francis Crick did us a major service by taking seriously and publicizing the problem of consciousness. But in the journal Nature he wrote, "Scientists need no longer stand by listening to the tedious arguments of philosophers perpetually disagreeing with each other. The problem of consciousness is now a scientific problem."
I say, "Bravo!" Consciousness is a scientific problem! But Crick framed the problem in terms of an unquestioned set of philosophical dogmas; namely that the key to consciousness will be found in the brain, that that's literally where experience and thought take place. My book is not anti-science; it's a challenge to science to get serious. It's deluded to think we're free of philosophy.
I'd make two additional points.
Firstly, I don't think neuroscience is only in need of more philosophy and philosophers. I think scientists also need to pay attention to art: we can learn just as much from reading Virginia Woolf as we can from reading Dan Dennett or Alva Noe. As I've said before, novelists and philosophers aren't going to give you the answers - we need experiments for that. But To the Lighthouse can help scientists ask better questions.
Secondly, and this point just supports what Noe says, I think it's quite interesting how scientific questions about consciousness have grown more and more limited in scope over the years. Only a few decades ago, scientists were putting forth confident conjectures about "the bridging principle," the neural event that would explain how the activity of our brain cells creates the subjective experience of consciousness. All sorts of bridges were proposed, from 40 Hz oscillations in the cerebral cortex to quantum coherence in microtubules. These were the biological processes that supposedly turned the water of the brain into the wine of the mind.
But scientists don't talk about these kinds of bridging principles these days; the mind-body problem has become one of those intransigent mysteries we don't even bother to investigate. While neuroscience continues to make astonishing progress in learning about the details of the brain--we are a strange loop of kinase enzymes and synaptic chemistry--these details only highlight our enduring enigma, which is that we don't experience these cellular details. It is ironic, but true: The one reality science cannot reduce is the only reality we will ever know.
The limitations of the reductionist approach to understanding consciousness (at least so far) highlights the need, ala Noe, for a serious re-thinking of the questions we're asking. Reductionism is an astonishingly powerful empirical tool but that doesn't mean it can solve every unknown. William James said it best, as usual: "The systematic denial on science's part of personality* as a condition of events, this rigorous belief that in its own essential and innermost nature our world is a strictly impersonal world, may, conceivably, as the whirligig of time goes round, prove to be the very defect that our descendants will be most surprised at in our own boasted science, the omission that to their eyes will most tend to make it look perspectiveless and short."
*When James refers to "personality" I don't think he's simply referring to our Myers-Briggs score. Instead, I think he's referring to all those aspects of experience that aren't best described in terms of action potentials and nerve reaction times.
One thing I've recently read that is interesting, although maybe only somewhat connected to the exploration of consciousness, is physics experiments (of all things) into quantum entanglement that seem to point to a greater reality/Universe beyond our own - not necessarily spiritual or anything, but a reference frame that is completely outside our observable frame.