An individual has a theory of mind if he imputes mental states to himself and others. A system of inferences of this kind is properly viewed as a theory because such states are not directly observable, and the system can be used to make predictions about the behavior of others. As to the mental states the chimpanzee may infer, consider those inferred by our own species, for example, purpose or intention, as well as knowledge, belief, thinking, doubt, guessing, pretending, liking, (...) and so forth. To determine whether or not the chimpanzee infers states of this kind, we showed an adult chimpanzee a series of videotaped scenes of a human actor struggling with a variety of problems. Some problems were simple, involving inaccessible food as in the original Kohler problems; others were more complex, involving an actor unable to extricate himself from a locked cage, shivering because of a malfunctioning heater, or unable to play a phonograph because it was unplugged. With each videotape the chimpanzee was given several photographs, one a solution to the problem, such as a stick for the inaccessible bananas, a key for the locked up actor, a lit wick for the malfunctioning heater. The chimpanzee's consistent choice of the correct photographs can be understood by assuming that the animal recognized the videotape as representing a problem, understood the actor's purpose, and chose alternatives compatible with that purpose. (shrink)

In a series of papers, Sperber provides the following analysis of the phenomenon of ill-understood belief (or 'quasi-belief', as I call it): (i) the quasi-believer has a validating meta-belief, to the effect that a certain representation is true; yet (ii) that representation does not give rise to a plain belief, because it is 'semi-propositional'. In this paper I discuss several aspects of this treatment. In particular, I deny that the representation accepted by the quasi-believer is semantically indeterminate, and I reject (...) Sperber's claim that quasi-belief is a credal attitude distinct from plain belief. (shrink)