I’ve had just a few too many conversations in which somebody has said or implied the following:
“Ultimately, everything is physical, and all phenomena can be explained in terms of physical laws.”
Sometimes they then go on to say things like:
“Trying to talk about minds and consciousness as a fundamentally separate category is misguided: even if it’s helpful to describe them in their own category, and even if we don’t fully understand them yet, whatever is going on has got to essentially be physical processes subject to physical laws.”
Whether or not the conclusion is true, I think the argument is wrong.
This post, then, will serve as a sign for me to tap whenever physicalists, reductionists, and materialists start getting a bit too enthusiastic. In other words, I would like to drive them out of their bailies, and build my own motte.
Take the physicalist thesis:
Everything is physical, and all observable phenomena can be explained in terms of physical laws.
This is a slightly ambiguous claim, and the main ambiguity lies in ‘physical laws’: do we mean ‘the laws we currently have and understand’, or ‘the ideal laws we will one day discover’?
The first of these is obviously wrong. Theoretical physicists still do research. We don’t really get how pouring water works.
The second of these is much more defensible for a sufficiently generous notion of ‘ideal future laws’ - it’s hard to argue that some things simply could never be explained by any amount of science. (Although not impossible.)
But crucially, these are two very different claims. You can accept the second one without accepting the first one.
So when a straw reductionist says ‘silly [phenomenologist/dualist/idealist], obviously mental phenomena can only be explained in terms of physical laws and reduced to physical phenomena’, well, ask them if they mean ‘can’ as in ‘I can do it right now’ or ‘can’ as in ‘I believe that one day science will be able to do this’.
If it’s the second one, it isn’t obvious to me (but more on that later). But even granting that science will one day answer the hard problem of consciousness, well, how much do we know about what the answer will look like? It seems to me that it’s at least possible for it to require irreducible phenomena, or for fundamental things to behave and interact in a way unlike anything in our current theories.
And if it’s the first one, boy, I would love to see it.
I know it’s a bit of a trope for weird hippies who got too into philosophy to go up to the good proper intellectuals and say “but can your science explain this!” as they frantically brandish a magnet or a weirdly shaped leaf they found. But there are things science can’t explain! And, I would venture, a good way to make scientific progress is to actually look for those things. I’ve seen some very ambitious arguments about the future which, however technically rigorous, are not very philosophically rigorous, and unfortunately an argumentative chain is only as rigorous as its weakest link.