We defend the Simulation Theory of Mind against a challenge from the Theory Theory of Mind. The challenge is that while Simulation Theory can account for Theory of Mind errors, it cannot account for their systematic nature. There are Theory of Mind errors seen in social psychological research with adults where persons are either overly generous or overly cynical in how rational they expect others to be. There are also Theory of Mind errors observable in developmental data drawn from Maxi-type (...) false belief tests. We provide novel responses to several examples showing that Simulation Theory can answer these challenges. (shrink)