In recent academic philosophy, panpsychism has gone from being an object of public ridicule to being a respected minority view. A recent article by Olivia Goldman covered this development. A couple of neuroscientists, Anil Seth and Kevin Mitchell, have written strongly worded articles in response. There is a lot I could say in counter-response to Seth and Mitchell, but given time constraints I’ll restrict myself to making a few points:
Neither Seth nor Mitchell show any awareness of the reason academic philosophers have recently taken an interest in panpsychism
This is in fact due to the recent rediscovery of certain ideas from the 1920s of the philosopher Bertrand Russell and the scientist Arthur Eddington. In the public mind physics is on its way to giving us a complete account of the nature of matter. But what Eddington argued, building on Russell, is that physics is not a mirror of reality but a tool for prediction. The equations of physics do not tell us what physical properties – mass, charge, space, time – are, and if you try to extract for physics a definition of any physical property you’ll quickly find yourself looping back in a circle. But even if we don’t know the nature of physical properties, we can recognize them in the world, and by applying the equations of physics we can predict with great accuracy how matter will behave.
What has all this to do with consciousness? What Russell/Eddington are drawing our attention to is a huge gap in our scientific picture of the universe: physical science tells us nothing of the real nature of physical properties (there are corresponding gaps in higher-level physical sciences, assuming the properties of such higher-level sciences are ultimately constituted of the properties of physics). Eddington’s insight (again building on Russell) was that we could fill that gap with consciousness, by holding that consciousness properties are simply the real nature of physical properties.
It was previously thought that there were only two options for accounting for consciousness: physicalism (consciousness is to be explained in terms of physical science) or dualism (consciousness is something extra to the physical properties of the brain). Both of these views face profound problems (see the next point). Eddington’s panpsychism is attractive because it avoids the deep difficulties facing the other two options. It is not strictly speaking testable, simply because consciousness itself cannot be observed, but if it offers a more parsimonious and less problematic account of consciousness than its rivals, then this gives us strong reason to take it seriously (As I often point out in this context, special relativity is empirically equivalent to the Lorentzian view that preceded it, and yet the scientific community almost universally embraced it because it brought greater internal unity to physics).
The hard problem is, in the first instance, a philosophical problem.
The hard problem is rooted in a number of arguments, such as the knowledge argument and the conceivability argument, that purport to show that physicalism is incoherent. I can’t get into too much of the details here (although see the first half of my book for the full story), but the basic idea is that the purely quantitative vocabulary of physical science is not suited to characterising the qualitative properties of consciousness. You could not convey in the language of neuroscience what it’s like to see red (if you could, then the congenitally blind could in principle know what it’s like to see colours through reading neuroscience in braille); and if neuroscience can’t even convey these qualities then it certainly can’t explain them.
To be fair, Seth does say something about the conceivability argument, but what he says reveals deep confusions about how it’s supposed to work. Seth claims that it’s all about what can be imagined. But in the versions defended in the academic literature, e.g. by David Chalmers or myself, the focus is not on imaginability but on logical coherence. Logical coherence is not the kind of thing you can test in a lab or observe through a telescope. It’s the proper domain of careful philosophical reflection.
Which brings me to my third and final point:
This is symptomatic of the casual rejection of philosophy in contemporary culture
I would never dream of wading in and casually dismissing the views of Seth and Mitchell without careful engagement with their empirical work. Any yet they think they can casually dismiss the conclusions of academic philosophers without careful engagement with their arguments. This contrasts strongly with the attitude of Eddington. As Seth points out, Eddington is one of the most important experimental scientists of the 20th century. And yet he was also a keen reader of the leading philosophers of his day, while expressing due humility about it not being his own area of specialization (an attitude also exemplified by the contemporary physicist Sean Carroll, who – from the opposite side of the debate to me – bothers to give a careful examination of the philosophical arguments on consciousness in his recent book). I love the following quote from Eddington, concerning the work of his philosophical contemporary Alfred North Whitehead:
“Although this book [Eddington’s The Nature of the Physical World] may in most respects seem diametrically opposed to Dr. Whitehead’s widely read philosophy of Nature, I think it would be truer to regard him as an ally who from the opposite side of a mountain is tunnelling to meet his less philosophically minded colleagues. The only thing is not to confuse the two entrances.”
What a beautiful image to capture the spirit of collaboration that ought to exist between philosophers and scientists. And yet what we find in the twenty first century is scientists like Stephen Hawking and Leonard Mlodniow beginning a book by declaring that ‘Philosophy is dead’, before going on to do incredibly crude philosophy in later chapters. I love science; in fact I’m a huge fan of Seth’s work. But philosophy is important too. Let’s tunnel together.