Representational Content Joe Lau Philosophy HKU

Thalamus activity

The Simple Causal Theory

Neural Representation

Conceptual Representations Conceptual representations are “stimulus-free” No regular connections between the presence of a conceptual representation and stimulus in the environment.

“Meaning is Use” Wittgenstein : The meaning of a word is not some physical object or a mental image. “PLATO”

Conceptual Role Semantics The meaning of a mental representation depends on its role within the functional organization of the mind. Example : role of a concept in reasoning.

An Example Suppose we have someone who : Accepts “P und Q” as true if he accepts both “P” and “Q” as true. Accepts both “P” and “Q” as true if he accepts both “P und Q” as true. (“P”, “Q” stand for sentences.) What does “und” mean?

Changing the Example Suppose we have someone who : Accepts “P”  accepts “P und Q” Accepts “Q”  accepts “P und Q” Accepts “P” and “Q”  accepts “P und Q” Accepts “P und Q”, rejects “Q”  accepts “P” Accepts “P und Q”, rejects “P”  accepts “Q” What does “und” mean?

Fine-grained Meaning Same reference, different meanings Bill Gates : “Bill Gates is rich.” Bill Gates : “I am rich.” “I” and “Bill Gates” refer to the same person in both utterances, but they have different meanings. Meaning plays a role in psychological explanation.

Too fine-grained? If meaning = conceptual role, then any change in conceptual role amounts to a change in meaning. Change in belief amounts to change in conceptual role?

Example Here is a pig. So here is a stupid animal. Here is a pig. So here is an intelligent animal.

Response #1 Hard line : Change in belief amounts to change in meaning. But people can still communicate because their meanings are similar if not identical.

Response #2 : Part I Distinguish between dictionary and encyclopedia entries. Dictionary entries : essential (necessary) features of a thing. Pigs are animals. Bachelors are unmarried. Encyclopedia entries : contingent (non-necessary) features of a thing. There are pigs in Hong Kong. Uncle Sam is a bachelor.

Response #2 : Part II The content of a representation is not constituted by all its conceptual roles. Only those conceptual roles specified in the dictionary entries do. So acquiring new information might not change meaning if information is stored in the encyclopedia.