on what the Buddha taught
Some time ago I had my first few encounters with people claiming mind to be matter, as a product of the brain. I was then unaware of people having this view but the for me interesting part was to discover I had not questioned my own view on this matter at all. As long as I can remember I took for granted we have a mind, as the non-matter part of a being.
In support for their view they claimed to have gotten it from someone or somewhere else and asserted that with the right equipment we can see things lighting up in the brain, explained as the mind thus originating from the brain. Which to me is an odd conclusion. After all, what is looked at is matter (it is matter that is seen), how would this say anything about the non-matter part to begin with?
In terms of language mind and matter are two things, so there is that difference, but lets reason a bit further.
If two things are the same, there must be some sameness, at least within a certain context. A house differs from a store, so these are two different things. But on a more general level we can say that since both are buildings they can be seen as occurrences of a same thing. So we have two particulars (house & store) of a (more) general (building). A house differs from a cave and caves aren’t necessarily called buildings, so to see if they are particulars of a same thing we would have to go to an even more general level. Then we might end up with something like shelters. In the end the highest form of generalization of matter is a combination of hardness, cohesion, temperature and motion. These four great essences can be discovered by us through our senses and to some extend they can be shared; the tree I see can be seen by others too.
Thus if mind is matter then it must be possible to generalize it with these same qualities as well. So lets take anger for example. When we are angry we know that. But is it tangible? Visible (does light reflect)? Can it be tasted? Smelled or heard? Can it be shared?
When someone is angry there often are signs to see but again, that is just the matter part not the anger itself. And it might become more difficult to notice things like knowledge, trustworthiness, and so on. We can see that any of those things do not behave what we know of matter to be like at all. Not discoverable through our five senses and not shareable, not having this sameness on a very general level, then thus not the same thing. And being different things they then can’t be derived or originated from one another.
Now some might say ‘Well, then it is all energy’. If energy is assumed to be an even more general level then care should be taken because sooner or later we think of atoms, electrons, etc. which is just matter. Also it would then open the view to ‘matter is mind’ while ‘mind is matter’ was really meant to deny any non-matter in the first place. And if you are willing to let energy to be just an abstract, without anything concrete, then the question remains ‘to what end’?
Stating that mind is matter is really implying something about life-and-death, which in the end forms an excuse of why we live our lives the way we do. However we understand life to be, that forms our justification. In a way we could say the awakened one did view a more general level: suffering; but then gave us the antidote for it as well.