Hence, the judgment that Timmy expressed his idea in an incorrect manner is baseless, because there is no expression that is more correct for an idea. Thats true, but this is a fine line, and we need to pay attention to the difference between an expression and meaning.
Lets get back to the observer's POV. Timmy says: "666 is a prime number". From the observer's POV we have no access to the meaning, only the expression. So we must now attempt to interpret the utterance! But an expression can mean anything! Absolutely anything! If we don't interpret the utterance with the assumption of a particular language (for example, English) the utterance can basically mean anything! So in order to have a practical value for an expression, we must have some assumptions about the language this expression is constructed with. So, simply said, to interpret an expression we must have a reference language.
Can an observer say: "Timmy believes that 666 is a prime number. He also believes that prime numbers mean cool numbers." - Not really! We have already established that saying: "Timmy believes that 666 is a prime number" is not correct. And saying: "He also believes that prime numbers mean cool numbers" is again incorrect. He does not believe that the concept of primeness and coolness are synonymous. He only thinks that the utterance of 'prime number' and 'cool number' are synonymous. So when we say: "Timmy believes that 666 is a prime number", this is interpreted in our language not his, because its us who are making that utterance.
Consider the smart answer that Richard provided: I should have stipulated that Timmy intended to use his words in the same way as the rest of his speech community does (so when we tell him what the rest of us mean by 'prime number', he will respond, 'oops, my mistake').
That answer signifies an important realization: There is no right way or wrong way to express an idea, except in one case: When that expression has the goal of being correctly interpreted, and to communicate the idea that it means.
So we have two cases:
- The speaker is NOT concerned how his expression is understood. The expression is taken to have value in and of itself. Here there are no qualifiers to the rightness or wrongness of an expression.
- The speaker intends to convey an idea. The expression not the goal, the idea (meaning) is the goal. Here, it becomes important to express the idea in an understandable manner.
In this series:
Expressions And Meanings - Part 1: Introduction
Expressions And Meanings - Part 2: Elaboration
Expressions And Meanings - Part 3: Linguistic Relativism
Expressions And Meanings - Part 4: Conclusion