Well, your reasoning is not correct : if a radio is broken, it can;t play music. But music is not created inside the radio.

@IoannisPaizis - not quite the right analogy - if we had no idea if radios generated music, but if we broke them in a certain way the lyrics to a song and nothing else changed, we might reasonably conclude they created music. It's about scale and complexity of the changes.

My challenge here is "If all you have is a music making box and a hammer, can you really prove that it does not generate its own music?"

I do not consider reasoning as an intellectual game, but a way to get to the truth.

@IoannisPaizis prehaps better phrased as "If we can alter the lyrics, rhythm, tone and notes played by selectively breaking bits of the music box, does it generate its own music?" Sorry, I know this comes off as game playing, but I think it's a legitimate question - you pre-suppose that the brain is a radio, but I'm arguing that if we didn't know if a machine made music or merely played it, the ability to alter all aspects of the music by breaking bits of the machine with a hammer would suggest it made music.

I just say that the ability to brake, or alter the physical infrastructure (with an obvious result in the mind too) does not prove that the mind is a physical thing. It just proves that the mind and the brain have a strong relation.

Ionnanis Paizis' analogy is indeed not quite right; music is a thing that the properly functioning radio receiver makes. The apt analogy to a radio receiver is the radio transmission or the radio transmitter, which damaging the radio does not alter.

Or for another analogy, try car-driver dualism. We can permanently alter the state and capabilities of a car without damaging the driver, and we can significantly but impermanently alter the state and capabilities of the driver by damaging the car. We can observe much about the state of the driver by observing the function of the car, but identical car measurements may correspond to radically different driver states. The car and the driver are different things, made of different things, with such properties that a car without a driver rapidly becomes inert.

Not that that's necessarily an apt description of bodies and minds, or that exists-injury doesn't constitute partial evidence against dualism, it's just to indicate that "exists-injury iff not-dual" is a fallacy.

In biology, the mind is physical - it is a collection of electrical impulses, chemical reactions (and composition) and neuron connections. Religions have different definitions.

@mmomtchev I'm glad I am not a biologist, your vacations can't be very interesting.

@mmomtchev Citation needed. A lot of this discussion depends on a definition of 'mind', and maybe you know of a biological definition of mind that could be considered authoritative. If so, please give a reference. But what you described just sounds like a description of brain activity. Many biologists may believe that the mind is merely brain activity, but it's overstating your case to say that this is simply true in biology (leaving aside the issue of what 'physical' means).

Regardless of what variant of the radio/music analogy is most fitting to the mind/brain, Ioannis and g s are clearly right that the evidence from brain injury effects doesn't support the conclusion that "we know the mind is a physical thing". I see that in one statement, @lupe has backed off to a position of "can you really prove [that it isn't]?", shifting the burden of proof to the opponent. "Can you really prove (not X)?" is a far cry from "We know X."

I like this answer as it's a troubling one, but I don't agree with it. At best it proves that the mind is affected by the physical brain in some way. At worst it proves that the outward expression of the mind is affected by the brain in some way.

@LarsH - so, I guess we're struggling with definitions of a mind, which is always tough - I would like to suggest "your consistent personality and inner voice" as mind - so, what you believe, how you react to certain events, how you think about things or reason. All of those can be altered by chemicals or damage to the brain. I'm not sure of any properties of thought, emotion or action that can't be influenced in some way by physical things

Now, postulating the brain as transmitter - well, we get into Russell's teapot, very quickly - the simple system is "Thoughts are physical, and our brain a machine". Saying "but no, something exists outside of this" requires some evidence that something outside this simple system is needed. My big argument is "despite a lot of searching, we've yet to find any evidence of mind properties that cannot be altered by brain damage or chemicals" - if mind/body duality were true, we'd expect to see some intrinsic thing that could not be changed

This answer is equivalent to arguing that if a broken car doesn't move, it can't have a driver inside. Dualists demonstrate the immaterial aspect of the mind by showing things that the mind can do that aren't reducible to matter. Namely, being able to think the exact same unchanging concepts (e.g. a circle being always a circle) despite neurons, atoms &c changing in the meantime; or being able to grasp different concepts without forming meaningfully different physical representations between them (e.g. chiliagons vs circles).

@Mutoh - ah, but I'm arguing that with the right damage, you could not recognise a circle at all, either as an object in front of you, or the concept of circle - en.wikipedia.org/wiki/Visual_agnosia is an interesting example

@lupe RE: "we've yet to find any evidence of mind properties that cannot be altered etc", We are also sometimes surprised how much speech can be explained without relying on thought process at all (within certain constraints of course). Those who explain this call it "the speech habit". There is also no evidence that the mind itself is altered by these extrinsics; since all we have is a hammer or two, the only scientific certainty is that the interaction between the music box and the music is changed by them.

@lupe If the mind is purely physical then we should be able to create a mind, right? Or at least identify from physical examination what makes one mind aware and another not? Not really that long ago people thought that if you just gave a computer enough processing power than it would develop some kind of awareness, but that has not happened and we still have no idea how to make a computer aware, not even at the level of a roundworm. It's possible that we will get there some day but it's definitely still an open question.

@user3067860 - this might be a bit outdated - we can make agents with the same awareness as roundworms, and we're steadily moving up the animal scale. But, I take the point - I'd argue that we've steadily beaten bits that we thought were impossible - image recognition, language, etc. But, we're still off awareness. We're also still a long way off, say, being able to simulate a brain - the biggest supercomputer couldn't run an accurate simulation of all the neurons in a brain, by a few orders of magnitude