August 31, 2013, by Stephen Mumford

Let’s Get Physical

Philosophers develop their mental lives as much as anyone does. And academics, especially in the arts, put thinking first. But that sometimes leads us to neglect our physical being. It is essential to us that we are an embodied rationality, with a physical location and extent in space and time, exercising our free agency. It is through causation that we engage with the world.

Like many others, I have found scientific naturalism and indeed physicalism to be an attractive and modern philosophy. A physicalist believes that everything is physical and only physical. There need be no spiritual substances, no souls, angels or God. Yet it troubles me increasingly that we have so little grasp on what counts as the physical; and the more we examine it, the more ethereal it seems.

We may not know as yet what the physical really is. Physicalists face a dilemma (due to Carl Gustav Hempel) in explaining their commitments. It seems unwise for them to say that they are committed to the entities invoked in current physics. Our physics now is most likely incomplete. Indeed, it seems that every few years some new theory comes along concerning the fundamental basis of physics: string theory, superstring theory, M-theory, quantum field theory. So perhaps we should say that the physicalist is only committed to the entities invoked in the finished and finally true physics, whenever that might come along. But the problem with this is that it’s writing a blank cheque to physics. The entities in the finished physical theory might have none of the features we now believe physical matter to have. So the physicalist might be committing to something looking very different from what they expect.

Some years ago Arthur Eddington described the two tables in front of him. One was the table of everyday experience, coloured, hard and solid. The other was the table of physics, which was mainly empty space, containing molecules, protons, electrons and neutrons. We still thought of atoms as like billiard balls but just very small. Particulars as solid, extended and impenetrable chunks of matter have now virtually disappeared from the scene, though. What creates the appearance of solid macroscopic objects is probably some collections of fields, attractions and repulsions. Particles are no more than foci or compresences of these causal powers. Such powers can only be powers to create more powers. It all starts to sound rather immaterial.

I no longer class myself as a physicalist, not because I believe in ghosts or psychic entities but just because I have no solid grasp of what such a commitment entails. I certainly think that our physical embodiment is crucial to us. We are very much causally engaged beings. But I am no longer sure what it adds to say that our bodies, and even our minds, are made of physical matter. If I am a just bundle of causal powers, that may have to be enough.

Posted in MetaphysicsPhilosophy