a soul is something figurative that makes us who we are, our brain is just hardware, while our soul is a collective thing from processing our information and experiences. or something
monism basically says that if my one brain molecule or whatthefuckever was slightly the left, id be a different person, which is stupid, i am who i am because of me, my experiences and whatever, im not who i am because of maths and science.

bash me in the head and i have less hardware to process with, but that doesnt make me less of a person than i was, it just limits my capabilities.

although, monism has a few merits
what happens with the whole left/right side of the brain? creative people use the right side more and maths people use the left more. creativity is part of who a person is, and thats determined by the hemisphere of the brain?
and getting drunk? its a chemical reaction, but my soul changes a fair bit with every drink i have, how can a physical reaction have an effect on something that isnt quite physical?

eh, we are who we are, soul and brain are the same thing, souls are just an abstract thing that is us.
theres just more to our brains than we understand, whatever