The mistake people make with Nagel’s most famous work is focusing too much on the stupid bat, as neither the bat nor our inability to know what it’s like to be a bat is all the important to his argument. The misplaced emphasis makes people respond to Nagel as if he were making an epistemological point, rather than using an epistemological observation as part of an argument about ontology and science. As I read him, Nagel is arguing that the subjectivity of something like pain is essential–to talk meaningfully of pain is to talk about pain as experienced by a subject. This creates the epistemological gap highlighted by the bat example, but more importantly demonstrates the irreducibility of pain. Unlike phenomena that don’t have an essential subjective aspect, something like pain cannot be treated in the standard scientific way that strips away the subjective properties of our experience of a thing to arrive at an objective description it. Nagel’s example is lightening. As experienced lightning has various subjective properties. Strip these away and you still have lightening–being experienced as a bright flash in the sky is not part of what lightening is in itself. Not so, says Nagel, with pain. Strip away the subjective properties of pain and you’re changing the subject.
A recent example of misreading Nagel on all this is Peter Godfrey-Smith very fascinating and illuminating account of the mental life of octopuses. As Godfrey-Smith shows, by studying the neuroanatomy of the octopus we can arrive at some compelling ideas about its mental and cognitive architecture, which reveals some truly remarkable things about the relationship between a kind of central mind and somewhat autonomous mind-like controls in each of its arms. This in turn gives us some hints as to what it might be like to be an octopus.
This is all well and good–exemplary, really, of the kind of philosophy of mind the directly engages cutting edge research in relevant sciences. Great stuff. Godrey-Smith seems to think, however, that it has something to say to Nagel. Specifically, he seems to think it’s a point against Nagel that this kind of search enables to approximate in our imaginations something of what an octopus experiences. But even if this research–or some kind of virtual reality machine–were to enable us to completely experience the world as an octopus does–it wouldn’t touch Nagel’s point. Sensing this perhaps, Godfrey-Smith suggests that Nagel’s point may be that a third person account of something will never capture a first person experience of the same thing, and suggests while that’s true it’s not very interesting. I’m not sure it’s true, but I agree it isn’t horribly interesting either way. But in any case it’s not Nagel’s point either
In the end I think Nagel was a red herring here, and fortunately the interest of Godfrey-Smith’s piece isn’t much affected. Arguably the kinds of questions he’s trying to answer, and the progress he’s able to make, are more interesting than Nagel’s celebrated attempts to land a knock out punch on materialism. I’ll say something more about that in a second post.