The sentence "You have a green light" is ambiguous. Without knowing the context, the identity of the speaker, and their intent, it is not possible to infer the meaning with confidence. For example:
- It could mean you have green ambient lighting.
- Or that you have a green light while driving your car.
- Or it could be indicating that you can go ahead with the project.
- Or that your body has a green glow.
- Or that you have in your possession a light bulb that is tinted green.
Similarly, the sentence "Sherlock saw the man with binoculars" could mean that Sherlock observed the man by using binoculars; or it could mean that Sherlock observed a man who was holding binoculars. The meaning of the sentence depends on an understanding of the context and the speaker's intent. As defined in linguistics, a sentence is an abstract entity — a string of words divorced from non-linguistic context — as opposed to an utterance, which is a concrete example of a speech act in a specific context. The closer conscious subjects stick to common words, idioms, phrasings, and topics, the more easily others can surmise their meaning; the further they stray from common expressions and topics, the wider the variations in interpretations. This suggests that sentences do not have meaning intrinsically; there is not a meaning associated with a sentence or word, they can only symbolically represent an idea. The cat sat on the mat is a sentence of English; if you say to your sister on Tuesday afternoon: "The cat sat on the mat", this is an example of an utterance. Thus, there is no such thing as a sentence, term, expression or word symbolically representing a single true meaning; it is underspecified (which cat sat on which mat?) and potentially ambiguous. The meaning of an utterance, on the other hand, is inferred based on linguistic knowledge and knowledge of the non-linguistic context of the utterance (which may or may not be sufficient to resolve ambiguity). In mathematics with Berry's paradox there arose a systematic ambiguity with the word "definable". The ambiguity with words shows that the descriptive power of any human language is limited.
Natural languages are often ambiguous and at times misleading. We rely on context, voice inflection, and further conversation to provide clarity. English is an ambiguous natural language.
Consider the poorly written sentence “I am going to bike and run or swim.” It could mean:
- a) I am going to (bike and run) or swim.
- b) I am going to bike and (run or swim).
tautologies and pragmatics
A: 'I don't know what kind of toothbrush to get, there are toothbrushes with flexible heads, toothbrushes with different shaped bristles, toothbrushes hard bristles, soft bristles...'
B: 'Oh, a toothbrush is a toothbrush.'
Within this context, the tautology can be recognised as meaning something like 'it doesn't matter about all these frills, toothbrushes are essentially all the same'. It's not immidietly obvious how we manage to work out this interpretation though.
This same type of logic applies when God said: I am that I am. He meant that he has no explanation,preventing infinite regress of language,truth and metaphor.
See http://tautology.wikia.com/wiki/Tautological_expression for "beer is beer" from Maverick Philosopher.