Theory of Mind is the branch of cognitive science that investigates how we ascribe mental states to other persons and how we use the states to explain and predict the actions of those other persons. More accurately, it is the branch that investigates mindreading or mentalizing or mentalistic abilities. These skills are shared by almost all human beings beyond early childhood. They are used to treat other agents as the bearers of unobservable psychological states and processes, and to anticipate and explain the agents’ behavior in terms of such states and processes. These mentalistic abilities are also called “folk psychology” by philosophers, and “naïve psychology” and “intuitive psychology” by cognitive scientists.It is important to note that Theory of Mind is not an appropriate term to characterize this research area (and neither to denote our mentalistic abilities) since it seems to assume right from the start the validity of a specific account of the nature and development of mindreading, that is, the view that it depends on the deployment of a theory of the mental realm, analogous to the theories of the physical world (“naïve physics”). But this view—known as theory-theory—is only one of the accounts offered to explain our mentalistic abilities. In contrast, theorists of mental simulation have suggested that what lies at the root of mindreading is not any sort of folk-psychological conceptual scheme, but rather a kind of mental modeling in which the simulator uses her own mind as an analog model of the mind of the simulated agent.