Since the smallest particles of matter are indifferent, as far as we can tell (i.e. swapping one particle for another makes no difference in the physical state

Since the smallest particles of matter are indifferent, as far as we can tell (i.e. swapping one particle for another makes no difference in the physical state of the thing), then insofar as minds are individualized some kind of dualism is inescapable. This is because the mind must be at least an emergent phenomenon of some configuration, and the configuration is not affected by what particular particles make up the configuration.