Abstract
A philosophical zombie is a being physically indistinguishable from an actual or possible human being, inhabiting a possible world where the physical laws are identical to the laws of the actual world, but which completely lacks consciousness. For zombies, all is dark within, and hence they are, at the most fundamental level, utterly different from us. But, given their definition, this singular fact has no direct implications about the kind of motion, or other physical processes, the zombie will undergo within its own world. Under quite standard physicalist assumptions, such as certain assumptions about the 'initial conditions' of the zombie's world and that of the causal closure of the physical1, a zombie's behaviour, as well as its underlying physical state, should be indistinguishable from the behaviour and physical state of a genuine human being.