Neutral monism

Thomas Nagel [in Mind and Cosmos] begins with the clearest of materialism’s problems: the great difficulty it has explaining the subjective character of experience, the feel of our mental lives: the feel of seeing colours and tasting wine, the feel of thought itself. Despite all the careful work that has been done in this area over the past fifty years, for Nagel the problem is as recalcitrant as ever. Materialism does indeed struggle to give a good explanation of these features of our minds. However, if materialism were somehow true, it would seem not to be true. The view from inside a conscious physical system would be distinctive in ways that would make it hard to understand from a third-person perspective: having an experience is very different from describing that experience, regardless of what the system having the experience is made of.

This holds back some arguments against materialism, but problems remain. In response to them, Nagel outlines a form of ‘neutral monism’. Neutral monism has for some time been a fringe character in debates about the mind-body problem. It was developed in different forms by eminent figures in early 20th-century philosophy, including Russell and Dewey, but then faded. A neutral monist argues that the mental and the physical are both manifestations of something more basic. It is a mistake, according to this view, to try to explain mind in terms of matter, or vice versa (hence the term ‘neutral’). But it is also a mistake to think there are two fundamental ingredients of the world (as a dualist does), rather than one.

The unpopularity of the view notwithstanding, Nagel is right that neutral monism is the best alternative to materialism. He thinks we have a clear idea of what the mental and physical are, that we can see neither can be reduced to the other, and that the only way to make sense of the situation is to say that all of nature, at bottom, contains a bit of both. A different and to my mind more promising version of the view has a more critical flavour. It holds that standard ways of thinking about the mind-body problem are dependent on crude conceptions of both the mental and the physical. We think we have a clear and definite idea of what a ‘purely physical’ or ‘purely mental’ process is like, but our grasp of both is so poor that we do a bad job of thinking about how they might be related, and see a gulf that isn’t really there. Nature gives rise to what appear to us as ‘physical’ processes and ‘mental’ processes, but both arise from something that fits into neither of these crude categories. Nagel’s neutral monism, however, is more of the ‘glue the two together’ variety than this second, critical strain. He thinks we can see, even in advance of changes that may take place in physics, that ‘something must be added to the physical conception of the natural order.’