>>12746471>destroying a half of a persons brainThis was discussed at length in the book. Specifically, the process of dealing with epilepsy patients was formerly the corpus callostomy, where the central never in the brain was severed, effectively destroying the communication process between the two halves of the brain.
This lead to many patients suffering some pretty odd effects, where, for example, one patient described reaching for her blue dress, but her hand on the left side kept reaching for her red dress, not only once or twice, but to the point of having a battle of wills with her own mind and forcing her own hand to obey her outer command. (this is an oversimplification, and the explanation is more interesting in the book but the salient point remains valid). There are other examples of note too.
https://www.amazon.co.uk/Master-His-Emissary-Divided-Western/dp/0300188374 > factual in so far as people believe it is. This is the conundrum with the modern world anyway, as people always appear to follow their own truth.
