The hard problem of consciousness

Science explains a lot of things why the northern lights appear in the sky, how diseases spread across the world, or how the human body protects itself from viruses and bacteria. But can science explain one of the deepest mysteries of all; can it explain our conscious mental experiences? In this Wi-Phi video, we’ll explore this issue in what’s known as the hard problem of consciousness. Suppose you are at a gallery looking at a painting by Rothko. The top half of it is painted in a vivid red, while the bottom half is covered in a dull maroon. The person next to you is staring at it intensely. What is she seeing? Does she see the same colors as you do? What’s more, does she feel the same way you do when you look at the painting? Say you get chatting and you convince her to wear some techy headgear that scientists use to monitor brain waves. You can now see exactly what her brain is doing when she looks at the painting. Would this tell you <i>what it is like</i> for her to see the painting? If you think it does, then you must be assuming that we can study consciousness experience scientifically and that by studying what’s happening in the brain, we can understand conscious mental experiences. But is this actually possible? Can we understand conscious mental experience through scientific studies of the brain? According to the philosopher Thomas Nagel, an organism has conscious mental states if and only if there is something <i>'it is like'</i> to be that organism. So, there is something it is like to be a bat, a dolphin, the person next to you at the gallery, and— <i>you— there is something it is like to be you.</i> All of these creatures have various kinds of experiences that differ in interesting ways. By contrast, there is nothing <i>‘it is like’</i> to be a piece of cheese or a cell phone because none of these things have conscious mental states. There is also something it is like to have specific mental states. For example, the experience of <i>seeing</i> the northern lights is very different from the experience of <i>hearing</i> a loud drum kit, and these experiences, in turn, are very different from the experience of tasting the bitterness of coffee or the experience of feeling the grainy quality of sand in your hands. You might be thinking—hang on a minute, don’t we already know a lot about the brain? So, surely neuroscientists have a good understanding of all of these conscious mental experiences— right? Yes, they do—a bit. Neuroscientists are making a lot of progress in identifying some features that are correlated with consciousness. And while these scientists are hard at work underingstanding the brain and our conscious mental states, no one has yet given a complete scientific explanation of consciousness. Moreover, the problem isn’t about <i>identifying</i> the neural states that are correlated with consciousness. The question, instead, is how and why certain neural states (or any states for that matter) give rise to conscious experiences at all! The issue for some philosophers is then that we might not, <i>in principle</i>, be able to give a scientific explanation for consciousness. The problem we are engaged with here is what the philosopher David Chalmers calls ‘the hard problem of consciousness’: the problem of explaining how and why physical processing gives rise to experiences with a phenomenal character. But why is this so hard? According to Nagel, the essence of the problem of consciousness derives from the apparent fact that any scientific description of conscious states seems to be ‘compatible with the absence of consciousness’. Let’s look at a more familiar example: a drum kit. A drum kit, at its most basic form, consists of a snare drum, a bass drum, a high hat, and a ride cymbal. Let’s throw in some tom-toms and crash cymbals for good measure. Now if we get all these bits in the right arrangement, then we get a drum kit. In other words, we shouldn’t be able to imagine a case where we have all this and yet don’t have a drum kit. In the same way, if scientists arrive at a full account of consciousness solely in terms of what’s happening in the brain, it should be impossible for us to imagine these processes happening in someone’s brain without them being phenomenally conscious. But the problem is that <i>it seems like we can imagine such scenarios</i>. To see this, consider philosophical zombies. These aren’t the sorts of creatures you see in horror movies. <i>Philosophical zombies</i> are creatures that are physically exactly like you or I, but which lack consciousness. These zombies talk and walk like us. They get around, go to work, have dinner, and even dance. Importantly, they also have the same brain processes as us. They just lack consciousness—there is nothing <i>it is like</i> to be a philosophical zombie. Can you imagine such creatures? It seems like we can. But if that’s right, it suggests that consciousness can’t be identical to all of the physical processes in our brain. It is important to be clear here that no one denies that neural states are relevant for consciousness. The issue is whether we can say that consciousness is nothing above and beyond what goes on in the brain. And it seems that as long as the hard problem remains unsolved, we can’t really be justified in saying this. Back in the gallery standing next to your new friend, you check the fancy brain-monitoring device she’s wearing to see what her brain is doing as she stares intently at the Rothko. Can you tell what she sees, what she feels? Until the hard problem is solved, we won’t really know. What do you think?