IMAGINE A PARTICLE:

In his book Until the End of Time (2020), the physicist Brian Greene sums up the standard physicalist view of reality: 'Particles and fields. Physical laws and initial conditions. To the depth of reality we have so far plumbed, there is no evidence for anything else.' This physicalist approach has a heck of a track record. For some 400 years - roughly from the time of Galileo - scientists have had great success in figuring out how the Universe works by breaking up big, messy problems into smaller ones that could be tackled quantitatively through physics, with the help of mathematics. But there's always been one pesky outlier: the mind. The problem of consciousness resists the traditional approach of science.

To be clear, science has made great strides in studying the brain, and no one doubts that brains enable consciousness. Scientists such as Francis Crick (who died in 2004) and Christof Koch made great strides in pinpointing the neural correlates of consciousness - roughly, the task of figuring out what sorts of brain activity are associated with what sorts of conscious experience. What this work leaves unanswered, however, is why conscious experience occurs at all.

There is no universally agreed-upon definition of consciousness. Awareness, including self-awareness, comes close; experience perhaps comes slightly closer. When we look at a red apple, certain neural circuits in our brains fire - but something more than that also seems to happen: we experience the redness of the apple. As philosophers often put the question: why is it like something to be a being-with-a-brain? Why is it like something to see a red apple, to hear music, to touch the bark of a tree, and so on? This is what David Chalmers called the 'hard problem' of consciousness - the puzzle of how non-conscious matter, responding only to the laws of physics, gives rise to conscious experience (in contrast to the 'easy problems' of figuring out which sorts of brain activity are associated with which specific mental states). The existence of minds is the most serious affront to physicalism.

Tweet   @brothersjudd