Consciousness—whatever its relation to neural events—is divisible. And just as it isn’t shared between the brains of separate individuals, it need not be shared between the hemispheres of a single brain once the structures that facilitate such sharing have been cut. If some way of linking two brains with an artificial commissure were ever devised, we should expect that what had been two distinct persons would be unified in the only sense that consciousness is ever unified, as a single point of view, and unified in the only sense that minds are ever unified, by virtue of common contents and
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