Comment 17 by Steve Zara :

Comment 15 by logicophilosophicus

Personally I think awareness itself, and probably also volition, will require new physics. I'd certainly regard it as an unwarranted act of faith to assert that the known particles and forces, as of this moment in time, MUST be entirely sufficient to explain free will, intention, purpose, ethics, value and the rest.

I often come across this view. It seems reasonable to some, because when you look at conventional physics it doesn't appear to have what is needed for awareness and so on. However, it doesn't take much thinking to show that this view simply doesn't work.

There seems something odd about this argument. Why couldn't the same thing have been said about the photoelectric effect at the beginning of the 20th century? In this case it did take new physics to account for it.

Firstly, if there is something that seems so strange about awareness that the physics we know doesn't appear to be sufficient, then there is no reason to expect adding more physics will help. The problem is that awareness seems strange and irreducible, so adding more physics which we understand won't assist with removing the strangeness or make it seem any less irreducible.

The argument here cuts both ways. It could be taken as an argument for the absolute irreducibility of mental phenomena as you are arguing that if present day physics will does not account for the mental then no physics ever will. One who thought that such reduction is impossible would agree with you here.

Secondly, awareness cannot in fact be irreducible. We have evidence of its reducibility from the fact of us being able to talk about it!

I don't understand what you are trying to say here.It looks like a non-sequitur to me, but I will see if your elucidation helps:

Talking about it arises from the firing of neurons in the brain, and so awareness must, through its presence, mean that some brain cells are active that otherwise would not be, and therefore there must be some aspect of awareness that involves normal physics, because brain cells don't fire because of magic.

I still don't see what you are getting at. I don't think even Descartes would disagree that "there must be some aspect of awareness that involves normal physics." And I don't see that someone who thought that some new physical principles were needed to account for awareness would be committed to the thesis that brain cells can fire because of magic.

Thirdly, because brain cells don't fire because of magic, there can't be any physical evidence for any new physics.

If brain cells don't fire because of magic, then if some new physics is needed to account for it then we would expect to be able to find physical evidence for it. In other words it is, in the end, an empirical fact whether there is any new physics.

Because brain cells don't break the principle of conservation of energy, any new physics must have effects that when summed up add to precisely zero. It must have the same effect as nothing.

This is a very curious thing to say. Couldn't a similar argument be used to preclude any advances in physics whatsoever?

The third reason is called 'causal closure', and is why only a minority of philosophers now accept the idea of dualism, that there is more going on than conventional brain activity.

'Causal closure' is a somewhat vague term. It seems to mean something like "Every event in the physical universe has a description according to which it falls under some universal scientific law." It is quite possible to accept that and to accept either property dualism or substance dualism.

There is another reason to reject the idea of new physics, and involves the recent discovery of the Higgs boson! This discovery means that we understand physics pretty well up to energies a million million times higher than anything that happens in the brain.

Another non-sequitur. You might as well argue that because relativity theory is quite good at describing the behaviour of galaxies that are millions of times larger than elementary particles it must be good at describing their behaviour too.