selfless flatworms

I find the notion that each sentient creature must have some discrete identity, or 'self' to be very natural.

I assume this discrete identity evolves from a combination of awareness of one's environment, and the creature's unique perspective of that environment.

Similarly, I cannot imagine my own self to be in more than one place at a time, or to simultaneously experience more than one perspective. Nor do I assume the 'self' of another person to be in any way related to mine.

However, some creatures, like flatworms are completely divisible. -That is, after a flatworm is cut in two, it is possible for each half to regenerate and become another full flatworm.









Now, if we assume flatworms have any degree of 'self', based upon its unique perspective and limited sentience, what can we say becomes of that 'self' when the flatworm is split in two (1)?

It is known that humans can survive a hemispherectomy, where one half of the brain is removed. Although it is technically impossible at present, it seems reasonable that a resected hemisphere could be transplanted into a donor body lacking both hemispheres. Would this operation split a human's 'self' in two?

1. To me this seems particularly challenging to any faith that would attribute a soul to a flatworm. Thus, it seems each time a flat worm is cut, a soulless flatworm is created, or another new soul is needed to fill the extra flatworm.