Archive | January, 2017

Galileo, Panpsychism, and the Hard Problem of Consciousness

28 Jan

Panpsychism and the hard problem

It is sometimes said that consciousness is a mystery in the sense that we have no idea what it is. This is clearly not true. What could be better known to us than our own feelings and experiences? The mystery of consciousness is not what consciousness it is but why it is.

Neuroscience has made considerable progress in understanding the physical mechanisms underlying human behaviour and associated internal functioning. But no one has even the beginnings of an explanation of why some physical systems, such as the functioning brain of a waking human, have experiences. Modern brain imaging techniques have provided us with a rich body of correlations between physical processes in the brain and the experiences had by the person whose brain it is. We know, for example, that a person undergoing stimulation in her or his ventromedial hypothalamus feels hunger. But no one knows why these correlations hold. It seems perfectly conceivable that ventromedial hypothalamus stimulation should do its job in the brain without giving rise to any kind of feeling at all. This is the difficulty David Chalmers famously called ‘the hard problem of consciousness.’

Materialists hope that we will one day be able to explain why consciousness exists in terms of wholly non-conscious physical processes in the brain. But this project now has a long history of failure. The problem with all extant materialist ‘solutions’ to the hard problem is that they always end up redefining consciousness. They start off by declaring that they are going to solve the hard problem: to explain experience itself. But somewhere along the way they suddenly start using the word ‘consciousness’ to refer not to experience but to some complex behavioural functioning associated with experience, such as the ability of a human to monitor its internal states or to process information about the environment. Explaining complex forms of behaviour is an important scientific endeavour. But the hard problem cannot be solved by changing the subject.

I am drawn to an alternative research programme. Instead of trying to explain consciousness in terms of utterly non-conscious brain processes analytic panpsychists hope to explain biological consciousness (i.e. the consciousness of humans and other animals) in terms of simpler forms of consciousness. These simpler forms of consciousness are then postulated to exist in basic forms of matter, ultimately the smallest constituents of the brain (whatever they turn to be). The panpsychist hypothesis is that the ultimate constituents of the physical world, perhaps quarks and electrons, have very basic forms of experience and that the complex experience of human and animal brains is grounded in the simple experience of basic matter. Twenty years ago panpsychism would have been immediately dismissed by scientists and scientifically minded philosophers, if indeed it was thought of at all. More recently, perhaps because of the dismal track record of materialist explanations of consciousness, a growing minority of philosophers and neuroscientists have been seriously exploring the potential of panpsychism to solve the hard problem.

This is not to give up on the hope for a scientific account of consciousness; analytic panpsychism is a scientific project in its own right (albeit at a very early stage of development). Of course the most basic forms of consciousness do not themselves end up getting explained. But, as Wittgenstein said, explanation has to end somewhere. Every theory must have its primitives. The only question is whether and how well they account for the data.

The philosophical foundations of physics

Most philosophers and scientists still hold out hope that consciousness can be explained without postulating additional entities, whether souls or micro-level consciousness. This hope is commonly supported with a bold narrative about the successful history of the physical sciences. At every point in this glorious history, it is claimed, philosophers have declared that certain phenomena are too ‘special’ to be explained by physical science – light, life, chemistry – only to be subsequently proven wrong by the relentless march of scientific progress. There is every reason, then, to expect that consciousness will go the same way, despite the naysaying of philosophers.

However, there is a different way of thinking about the history of physical science and its undeniable and rightly celebrated success. Perhaps the most important move in the scientific revolution was Galileo’s declaration that mathematics was to be the language of natural science. But he felt able to do this only after he had revolutionised our philosophical picture of the world. Before Galileo it was generally assumed that matter had sensory qualities: tomatoes were red, paprika was spicy, flowers smelt sweet. But it’s hard to see how these sensory qualities – the redness of tomatoes, the spicy taste of paprika, the sweet smell of flowers – could be captured in the abstract, austere vocabulary of mathematics. How could an equation capture what it’s like to taste spicy paprika? And if sensory qualities can’t be captured in a mathematical vocabulary, it seemed to follow that a mathematical vocabulary could never capture the complete nature of matter.

Galileo’s solution to this problem was to strip matter of its sensory qualities and put them in the soul. The sweet smell isn’t really in the flowers but in the soul of the person smelling them; the spicy taste isn’t really in the paprika but in the soul of the person tasting it. Even colours, for Galileo, aren’t really on the surfaces of objects but in the soul of the person observing them. And if matter had no qualities, then it was possible in principle to describe it in the purely quantitative vocabulary of mathematics. This was the birth of mathematical physics.

But of course Galileo didn’t deny the existence of the sensory qualities. Rather he took them to be forms of consciousness residing in the soul, an entity outside of the material world and so outside of the domain of natural science. In other words, Galileo created physical science by putting consciousness outside of its domain of enquiry. If Galileo was to time travel to the present day and be told there is a ‘hard problem’ of how to explain consciousness in terms of physical brain processes, he would no doubt reply, ‘Of course there is, I created physical science by taking consciousness out of the physical world!’

This does not, in itself, constitute an argument that there will never be a purely physical account of consciousness. But it does undermine arguments which appeal to the historical success of physical science in order to support the claims that physical science will one day solve the hard problem. The fact that physical science has done extremely well since consciousness was set outside of its domain of enquiry gives us no reason to think that it can adequately account for consciousness itself.

Is consciousness a datum in its own right?

It is twenty years since David Chalmers declared consciousness a ‘hard problem’. Although there is broad agreement that it is, this is often accompanied by vague statements that the problem will go away if we just do a bit more neuroscience. It’s time philosophers and scientists decided whether or not consciousness is a datum in its own right, on equal footing to the data of third-person observation and experiment.

Philosophers like Daniel Dennett and Keith Frankish deny that consciousness exists. This is their solution to the hard problem, and it’s a consistent (if rather implausible) view. Most philosophers believe that consciousness exists but refuse to make postulations in order to account for its existence. They try instead to squeeze it into the world of things we already believe in, things postulated to explain the data of observation and experiment. This research project hasn’t gone well.

If we believe in consciousness, we have to be prepared to make postulations in order to account for its existence. Panpsychism looks to be the most promising way of doing this, avoiding the well-known difficulties associated with the postulation of souls. Perhaps it won’t ultimately work out. But at the moment the serious interdisciplinary work needed to find this out is being hampered by an ideological insistence on the materialist paradigm; an ideological insistence not so dissimilar to that experienced by Galileo from the 17th century Catholic Church.