A mental state is a condition attributed to a cognitive system, such as a belief, desire, intention, perception or feeling. Experimental psychology studies such states through operational measures and predictions about behavior. Two people can see the same event yet hold different beliefs because they have different prior information. Distinguishing the state itself from the evidence used to infer it is central to studying social cognition. [ref]
A motivational attitude toward an outcome. Attributing a desire is distinct from establishing what an agent believes about how the outcome can be achieved.
A state directed toward bringing about an action or outcome. Inferring an intended goal from behaviour need not imply representing every belief or reason of the agent.
A state with representational content taken to be true. Attributing another person’s belief requires distinguishing its content from one’s own knowledge of the actual situation.
A belief whose content differs from the actual state of affairs. A false belief is distinct from ignorance: an ignorant agent need not have any particular mistaken representation. False-belief understanding is the capacity to represent and reason about this difference.
