 Here is another way to make the point. ST is made up of two distinct claims: the first is that mental simulation is psychologically real, i.e., that there are mental states and processes satisfying  RES+REU  and  PROC.  The second claim is that mental simulation plays a central role in mindreading. Clearly, the second claim cannot be true if the first is false. However, the second claim can be false even if the first claim is true: mental simulation could be psychologically real, but play no role in mindreading at all. Hence, Simulation Theorists have to do three things. First, they have to establish that mental simulation is psychologically real. We consider this issue in  section 3.  Second, they have to articulate ST as a theory of mindreading. That is, they have to spell out in some detail the crucial role that mental simulation is supposed to play in representing others’ mental states, and contrast the resulting theory with other accounts of mindreading. We dwell on this in sections  4  and  5.  Finally, Simulation Theorists have to provide evidence in support of their theory of mindreading—that is, they have to give us good reasons to believe that mental simulation does play a crucial role in representing others’ mental states. We discuss this issue in  section 6.