 In sections 2, 3, and 4 we dwelt upon the “internal” disagreements among Simulation Theorists. It goes without saying that such disagreements are both wide and deep. In fact, different Simulation Theorists give different answers to such fundamental questions as: “What is mental simulation?”, “How does mental simulation contribute to mindreading?, ‘What is the role of introspection in mindreading?” In light of such differences of opinion in the simulationist camp, one might conclude that, after all, Stich and Nichols (1997) were right when saying that there is no such thing as the Simulation Theory. However, if one considers what is shared among Simulation Theorists, one will realize that there is unity amidst this diversity. A good way to reveal the commonalities among different versions of ST is by contrasting ST with its arch-enemy, i.e., the Theory-Theory of mindreading. This is what we do in the next section.