The ‘hard problem’ is the problem of understanding how consciousness fits into the world described by science. The scientific world view has shown that many familiar things are really nothing more than arrangements of fundamental physical stuff: water is loosely connected H2O molecules; temperature is mean molecular kinetic energy; lightning is atmospheric electrostatic discharge; and so on.
Our conscious mental life, however, seems to resist this treatment. In recent years there have been great advances in neuroscience, and we now know a great deal about the ‘neural correlates’ of conscious mental states. With the help of magnetic resonance imagery and similar techniques, we can tell which regions of the brain become active when we have different conscious experiences.
It seems quite unsatisfying to be told that pain is nothing but the nociceptive activation of cortical regions.
Even so, it seems quite unsatisfying to be told that the experience of seeing something as red is nothing but a certain neural oscillation in the visual cortex, or that pain is nothing but the nociceptive activation of cortical regions. These claims seem to leave something unexplained, in a way that the other scientific claims do not. We want to ask why those oscillations in the visual cortex give rise to feelings of red rather than green, or indeed why they give rise to any conscious feelings at all, in a way we don’t ask why H2O gives rise to water, or electrical discharge to lightning. In short, the science of consciousness seems to leave us with an ‘explanatory gap’, as Joseph Levine has put it.
Different philosophers have different reactions to to this hard problem. Many take it to point to some deep truth about the nature of consciousness, and infer that we need some radically new kind of science to solve the problem. In my view, that’s making a meal of it. I don't think the problem is really that hard. In truth, experiencing red or feeling pain are indeed nothing but cortical oscillations, just as water is H20 and temperature is mean kinetic energy. The scientific evidence is overwhelming. No modern neuroscientist thinks that anything apart from physical brain processes are needed to explain how humans operate.
The flaw lies in us, not in the neuroscientific account of consciousness.
The problem, if there is one, is that we find the reduction of consciousness to brain processes very hard to believe. The flaw lies in us, not in the neuroscientific account of consciousness. Despite all the scientific evidence, we can’t free ourselves of the old-fashioned dualist idea that conscious states inhabit some extra dualist realm outside the physical brain.
Just consider how the hard problem is normally posed. Why do brain states give rise to conscious feelings? That is already dualist talk. If one thing gives rise to another, they must be separate. Fire give rise to smoke, but H2O doesn’t give rise to water. So the very terminology presupposes that the conscious mind is different from the physical brain—which of course then makes us wonder why the brain generates this mysterious extra thing. On the other hand, if only we could properly accept that the mind just is the brain, then we would be no more inclined to ask why ‘they’ go together than we ask why H20 is water.
https://www.youtube.com/embed/XiLfJopyLHs?wmode=opaque
If this is the right diagnosis of the hard problem, should we expect it to go away? It depends on why dualist ideas are so seductive. One possibility is that the grip of dualism is relatively superficial, deriving perhaps from the extent to which everyday thought is influenced by traditional religious ideas. If that is right, then maybe increased familiarity with science will in time stop people feeling there is anything specially puzzling about consciousness.
Perhaps, however, the explanation of dualist thinking lies deeper. Maybe we have some cognitive glitch that will stop us ever fully freeing ourselves from the idea that the conscious mind transcends the physical brain. If so, then we will simply need to learn to live with this dualist intuition, while at the same time recognizing that it has no rational basis. After all, the refutation of deep-seated intuitions is common enough in science. Most people still find it hard to believe that the earth is spinning, or that stones are mostly empty space, or that simultaneity is relative—yet science has shown that these things are true. Similarly, I say, we should accept that science has shown that the conscious mind is just the brain, even if something keeps telling us that it isn’t.