What would be the outcome, he muses, if one person received transplants from the brains of others? If it’s not possible, there may be a good reason why not:
If tiny bits of the brains from all the people in my neighborhood were transplanted into my brain, would there be a neighborhood in my skull?
Now consider this: what if a small part of my neighbor’s brain—say, a piece of his temporal lobe that mediates memory — were transplanted into mine? Who would have the memories? The answer is that, unlike the previous scenarios, this kind of transplant is not currently possible, and there is no objective reason to think that it ever will be.
Central nervous system tissue, including brain tissue and spinal cord tissue, does not regrow function when cut. Perhaps it will be capable of functional regrowth someday. Many neuroscientists think that functional healing of cut brain or spinal cord tissue will someday be possible. But that is hope, not science driven by data. I stress that there is no scientific reason to think it will happen. Brain and spinal cord tissue are quite unique in this sense — most body parts will functionally heal and can be transplanted, but not brain tissue.
I’m going out on a limb here, but I believe the intelligent design perspective may offer insight into the peculiar inability of central nervous system tissue to regenerate. We tend to think of the design perspective in terms of functional ability — e.g. the ability of DNA to code for genes or the ability of ribosomes to manufacture proteins, etc., as evidence for design. But we should also consider biological inabilities as possible manifestations of design…
Michael Egnor, “Are human brain transplants even possible?” at Mind Matters News
Good point. Sometimes what isn’t there is an instance of design. Not always just what is there.
Here’s the discussion from last Wednesday: Are head transplants soul transplants?
Michael Egnor: Are head transplants soul transplants? Specifically, if your head were transplanted, would your soul go with it? Because a human head transplant would induce quadriplegia, many philosophical questions are currently theoretical — but fascinating nonetheless.