Is consciousness a purely physical phenomenon with solely physical properties? According to a physicalist argument for consciousness, the answer is yes. Perhaps unfortunately, we have tied ourselves in a philosophical and scientific knot that prevents us from confidently stating that this is the case. Let us take a dive into the famous “hard problem of consciousness”. The hard problem of consciousness, formulated by the philosopher David Chalmers, confronts the difficulty of explaining the relationship between physical processes (i.e. brain processes) and experience (i.e. mental states or qualia). Simply put, the problem is that even if we can describe the physical processes in the brain that integrate and categorize information, it still does not answer why these processes are accompanied by experience. For example, a certain firing of neurons (which can be monitored using techniques like FMRI) occurs when I eat a leaf of basil, but we cannot know WHY the firing of those neurons generates the specific experience it does. Why not a different experience? Another example is why certain nerve stimulation causes pain rather than pleasure, and vice versa. I was reading about a particularly interesting anti-physicalist thought experiment (known as the knowledge argument) that drives home one aspect of the hard problem of consciousness. The experiment considers a human super-scientist who is locked in a black-and-white room with limitless logical acumen and learning material on the physical world. The person learns the entirety of all physics, chemistry, biology, etc., eventually leaving the room and experiencing color for the first time. Jackson (1982) makes the point that even though the person has a perfect knowledge of the physical world, they must uncover new truths about what it is like to see in color once leaving the room. In other words, there are absolute truths about consciousness that cannot be deduced from a limitless knowledge of the physical. It is like something to experience color, and we don’t know why. Many scientists and philosophers consider the hard problem of consciousness to be unanswerable.