Informational Content

Informational content is the theory that mental representation can be naturalized by treating mental states as carriers of information, in the sense defined by Claude Shannon's mathematical theory of communication. A mental state carries the information that P if the conditional probability of P given the state is high — ideally, if P is certain when the state occurs. On this view, a belief about rain is a state that carries the information that it is raining, because rain makes that state probable.

Fred Dretske and Jerry Fodor developed the most influential versions. Dretske argued that information requires nomic dependence: the state must lawfully correlate with the condition it represents. Fodor added that content requires asymmetric dependence: the state must carry information about the target even in situations where other causes could produce the same state, but it must not carry information about those other causes in the same way.

The theory faces a dilemma. If the correlation is perfect, content becomes infallible — but mental states clearly can misrepresent. If the correlation is imperfect, the theory cannot uniquely determine content: a state that correlates with both rain and lawn sprinklers carries information about both, and the theory needs an extra principle to say which is the content. Neither horn has been fully resolved.