Ben Conroy
Everyday philosophy
Sometimes it’s worth doing philosophy because it has some immediate practical implications, changing what you think is right or the way you live your life. But sometimes it’s worth doing because reality is wonderful, and contemplating it is good in itself.
Philosophy of mind is worth thinking about for both reasons. There are a lot of practical implications that arise from understanding the fundamental nature of our minds. But philosophy of mind is also just fascinating. We’re interested in discoveries about distant stars even if we don’t think they’ll help us invent a new kind of microwave. I think we should extend the same sort of interest to our own minds.
And there are some fascinating questions about our own minds that can’t be answered by neuroscience or psychology. Take the question of whether our minds and the thoughts in them are physical or not.
Physical things are made of matter. They’re detectable and measurable by the scientific method. They have a defined location – you might not be able to point at every physical thing and say ‘there it is’ but every physical thing is somewhere. Physicalism, the view that everything is physical (or more precisely, that all facts are physical facts) is a pretty popular view among modern philosophers. Catholics are going to be sceptical, but even before you get anywhere near religion, there are things about our minds that make fitting them into the realm of the physical difficult.
As an example of something physical, let’s take a trusty table. Our reality includes, among other things, plenty of tables. But our reality also includes people’s experiences of tables, their thoughts about tables, and their mental images of tables. You’re probably imagining a table right now. Allow me to draw your attention to some odd features of that image.
First of all: where is it? When you imagine a table, where is that image located? We say that the things we imagine are ‘in our heads’: but if you give this a bit of thought it’s not clear what it means. An image of a table printed on a piece of paper is really located on the paper. I can point to it and say ‘there’s a nice picture of a table’, and I’m not lying. But where are mental images? If we point at our heads and say ‘there’s a nice picture of a table in here’, we don’t mean that a dissection of the brain would yield a tiny pencil-sketch. It’s not obvious that the image actually has any physical location – that there’s any place that I could point to and say ‘there’s my image of the table there.’
We might be moving too fast here. Aren’t our mental images ‘in’ our brains in the same way that an image is ‘in’ a computer hard drive?
I don’t think this works. A computer might be said to be ‘storing an image of a cow’ on its hard drive. But what that means is that a computer has stored a string of instructions from humans which allows it, when given further instructions, to generate an image of a cow on a screen or on a piece of paper. The actual image is not physically ‘in’ the hard drive: that is not its location. If you looked very closely at the inner workings of the hard drive, you would see many things, but a cow would not be among them.
If we ask what mental images are made of, we get an equally odd answer. Physical things, after all, are made out of matter: cells, atoms, neutrons, quarks. What is a mental image made of? We might say it’s made of electrical signals, or of the neurons in our brain. But again, we don’t actually mean this in the way that a printed image is made of paper and ink. We’re not saying that our neurons are arranged to look like a table. Sure, certain electrical signals passing through our neurons seem to cause us to have certain mental images: but the images are not made of those signals. It doesn’t seem at all obvious that mental images are made of matter at all.
Two major features of physical things (having a spatial location and being made of matter) do not seem to be true of mental images. It starts to look like some of the contents of our minds are not actually physical at all.
These oddities are the starting points for arguments, not the end of them. Physicalist philosophers of mind have advanced clever cases for why the contents of our minds are completely physical after all. These have in turn been argued against by non-physicalists. But it’s only through philosophy, not science alone, that we can find the answer to this question about the fundamental nature of our minds.