Dualism versus materialism; addendum (Identity)

by dhw, Saturday, August 12, 2017, 10:48 (2446 days ago) @ David Turell

Although I felt obliged to give a detailed answer to all your arguments below, this addendum provides a good summary of the problem. It may be simpler for both of us if we use this as our basis for discussion.

DAVID: We covered the whole issue of size and complexity in my following entry:
Friday, December 16, 2016, 20:37 I suggest reading it again. Complexity of the neo-cortex is vital to sapiens brains being so different. 16 million neurons. Western gorilla has 9.1 million. Growth from 350 cc in Lucy like hominins to 1,300 cc is discussed. Each jump is not just size but a more complex cortex.

I am not disputing the increase in size and complexity. I am disputing your theory that God engineered the increases, and ONLY THEN were the respective hominins and homos able to come up with new ideas. Since you advocate the dualist concept of a soul that produces new ideas (and even survives the death of the brain), it cannot be the expanded/complexified brain that produces them! Therefore the expansion/complexification must be the RESULT of implementing the new ideas, as vividly demonstrated by the example of the illiterate women’s brains changing as a RESULT of their learning to read (which you have confirmed below).

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DAVID’s comment: H. sapiens wandered all over the globe. [...] Our brain's special capacity is the cause. Our closest cousins, the Neanderthals, did not wander. Their brains were bigger but less complex (it is assumed). Size and complexity of brain dictates what a species will develop. Size and complexity first, use second. It is so obvious. (dhw’s bold)
Dhw: […] During our last discussion you accepted the dualistic concept of we/the soul/consciousness as the source or “cause” of thought, and the brain as the provider of information and the means of implementing thought. which is the soul’s “use” of the brain.(Once again I should emphasize that I am not taking sides, but only trying to unravel the knots in your own dualistic arguments.)
DAVID: There are no knots. We settled this. It is obvious the soul uses the brain as an instrument. I am discussing the attributes of the instrument and what can be done with it by the soul.

Good. So why do you say the brain was the CAUSE of our wanderings, and the Neanderthals didn’t wander because their brains were less complex? Was it the brain that inspired Sapiens to wander, or did the soul instruct the brain to move the body? Or do you think Neanderthals wanted to wander, but your God had not made their brains complex enough for them to do it? How frustrating for them!

dhw: Yes of course the brain has to be plastic in order to implement the new concepts. (Pre-) Heidelbergus and (pre-)Neanderthals also had plastic brains, and these would have expanded or complexified in order to implement the new ideas, but (pre-)Sapiens had bigger and better ideas, and therefore they needed bigger and better or more complex brains to implement them.
DAVID: You are forgetting gaps. You are using Darwinian thinking again. The hominin fossil evidence shows each time a new species appears its brain size is 200 cc bigger, and more than likely has a higher complexity of its neurons and connections. That larger brain allows for more advanced ideation and more advanced artifacts to prove the point.

How can the brain “allow for more advanced ideation” if it is the soul that produces ideas? In your dualism, the brain implements the ideas provided by the soul, and the more advanced artifacts are the material realization of the ideas. Which comes first: ideas or implementation of ideas? If an idea requires something new from the brain, the brain must make changes to itself. Each expansion or complexification will therefore be the result of new demands. (See below).

dhw:So please make up your mind: are you a materialist (the brain is the source of thought) or a dualist (the “soul” is the source of thought)? If the "soul" is the source, it needs brain expansion or complexification to implement its ideas, and as is proven by the case of the illiterate women, complexification results from the effort to read.[...]

DAVID: Stop beating a dead horse. Sapiens brains appeared 300,000 years ago, no larger than Neanderthal, in fact smaller, implying more complexity on board, as shown by sapiens accomplishments compared to Neanderthal all living in competition. The woman you refer to are using an existing brain of specific size and complexity. They learn to read which results in known shrinkage in size and increase in complexity of an already existing brain size and advanced connectivity of more neurons. Your example is a total nonsequitor to our discussion of what causes 200 cc jumps in brain size. (dhw’s bold)

It is you who have (in my view rightly) combined the factors of size and complexity. Yes, the women had an existing brain of specific size and complexity, but the desire to read, as you so rightly say, RESULTED in increased complexity. The same process – the effort to do something new – would have RESULTED in expansion and/or increased complexity in earlier species of hominin/homo.