A topic that is so blindingly obvious that we might overlook it... or should I say, "that is so blindingly obvious to philosophers", but then the object of this site is to develop cross-disciplinary relations...
So, let's get it said: THE most important - indeed, some have said the ONLY - subject of philosophical investigation is language. This probably seems self-evident - I'd even go so far as to say that this SHOULD appear self-evident. Whatever we're talking *about* when we do philosophy, we are before all else *talking*. But HOW does language represent the things we're talking about? Is there an iconic or isomorphic relation between language and the world - that's to say, is the world structured into categories that correspond to the categories of language? We talk about 'objects', 'events', 'states', 'properties', 'relations' as if they were objective classes of 'things' or 'phenomena', when they rather correspond to our nouns, verbs (and verb forms), adjectives and adverbs, and prepositions and conjunctions.
Some might argue that our language shapes our beliefs about the world, and that in some way the world of objects, events, and the like is the *result* of the way our language is structured. Many nominalist views inherit this belief; but so do certain idealist views. An alternative account would argue that the categories of our language are determined by "the way the world is" - that language has evolved to communicate information based on the common capacities of human perception and neurological processing, and that these capacities have evolved in response to stimuli in our physical environment - we could call this the 'indexical' view of the relation between language and the world.
The 'indexical' view (the term comes from Peirce) sees the categories and structure of language as being an 'index' or 'clue' to the 'nature of the world'. However, it avoids 'naïve isomorphism' (the view that the structure of the world 'actually resembles' the structure of language) by suggesting a causal rather than a formal relation. To give an analogy: the first sign of chicken pox is a particular rash on the skin; anyone who's had 4 children will probably recognise it on sight. Chicken pox is caused by a virus; the rash is an index of the presence of the virus. However, the rash does not "resemble" the virus: the relation is one of contiguity, not of formal similarity.
Others might say that the real question lies elsewhere. Language is not primarily a matter of naming things in the physical world, but of human interaction. Such philosophers would point out that human beings engage in very different activities at different times and in different contexts; likewise, our language is not a monolothic structure in which grammatical elements always bear the same relation to some element or another of 'the world', but is rather a complex series of 'forms of action' in which the function of the putative 'grammatical elements' is entirely fluctuant. Language use, they would say, is determined by pragmatic rather than descriptive considerations; investigating its 'descriptive' capacities to the exclusion of all else is narrow-minded and restrictive.
There is an evident parallel between these remarks and discussions elsewhere in the group...