Language of Thought Hypothesis - Reception

Reception

Some philosophers have argued that our public language is our mental language, that a person who speaks English thinks in English. Others contend that people who do not know a public language (e.g. babies, aphasics) can think, and that therefore some form of mentalese must be present innately.

The notion that mental states are causally efficacious diverges from behaviorists like Gilbert Ryle, who held that there is no break between cause of mental state and effect of behavior. Rather, Ryle proposed that people act in some way because they are in a disposition to act in that way, that these causal mental states are representational. An objection to this point comes from John Searle in the form of biological naturalism, a nonrepresentational theory of mind that accepts the causal efficacy of mental states. Searle divides intentional states into low-level brain activity and high-level mental activity. The lower-level, nonrepresentational neurophysiological processes have causal power in intention and behavior rather than some higher-level mental representation.

Tim Crane, in his book The Mechanical Mind, states that, while he agrees with Fodor, his reason is very different. A logical objection challenges LOTH’s explanation of how sentences in natural languages get their meaning. That is the view that “Snow is white” is TRUE if and only if P is TRUE in the LOT, where P means the same thing in LOT as “Snow is white” means in the natural language. Any symbol manipulation is in need of some way of deriving what those symbols mean. If the meaning of sentences is explained in terms of sentences in the LOT, then the meaning of sentences in LOT must get their meaning from somewhere else. There seems to be an infinite regress of sentences getting their meaning. Sentences in natural languages get their meaning from their users (speakers, writers). Therefore sentences in mentalese must get their meaning from the way in which they are used by thinkers and so on ad infinitum. This regress is often called the homunculus regress.

Daniel Dennett accepts that homunculi may be explained by other homunculi and denies that this would yield an infinite regress of homunculi. Each explanatory homunculus is “stupider” or more basic than the homunculus it explains but this regress is not infinite but bottoms out at a basic level that is so simple that it does not need interpretation. John Searle points out that it still follows that the bottom-level homunculi are manipulating some sorts of symbols.

LOTH implies that the mind has some tacit knowledge of the logical rules of inference and the linguistic rules of syntax (sentence structure) and semantics (concept or word meaning). If LOTH cannot show that the mind knows that it is following the particular set of rules in question then the mind is not computational because it is not governed by computational rules. Also, the apparent incompleteness of this set of rules in explaining behavior is pointed out. Many conscious beings behave in ways that are contrary to the rules of logic. Yet this irrational behavior is not accounted for by any rules, showing that there is at least some behavior that does not act in accordance with this set of rules.

Another objection within representational theory of mind has to do with the relationship between propositional attitudes and representation. Dennett points out that a chess program can have the attitude of “wanting to get its queen out early,” without having a representation or rule that explicitly states this. A multiplication program on a computer computes in the computer language of 1’s and 0’s, yielding representations that do not correspond with any propositional attitude.