Well, it is certainly true that introducing unambiguous, very carefully defined, agreed terminology and having a perspicuous notation can make reasoning easier and make us less prone to common reasoning errors. To take the obvious example, mathematicians aren't just being awkward when they use a lot of symbolism and make very careful distinctions wrapped up into technical terms (and borrow from the languages of formal logic to make clear, for example, the 'scope' of their quantifiers). If proofs all had to be written out in unaugmented English, then we'd get lost following them, even in elementary high school algebra: and proof-discovery would be orders of difficulty harder.

I suppose we might say "mathematicians' English" -- meaning English augmented with their new definitions and notational devices -- is a new, better, language, more suited to (mathematical) reasoning than street English. But equally, we might say that it is just one part of a single inclusive language, modern English: it is just a part that is only learnt by those with certain specialist interests. But for present purposes I can't see that it really matters which of those descriptions you prefer. The key point remains that, yes, appropriate linguistic devices, e.g. sharply defined terms and a perspicuous symbolic notation, certainly can expedite reasoning and help us avoid error.

Philosophers of language explicitly deal both with issues concerning all possible languages and with issues concerning just human languages. They usually make clear which of the two they are discussing at the time.

I take it that by "bivalence", you mean the principle that every proposition is either true or false. And if we take that principle in unrestricted form---we really do mean every proposition---then, well, it's hard to see how it could fail to imply that the proposition expressed by "There will be a riot in London on 13 January 2076" is either true or false.

If you don't like that conclusion, then you have to abandon bivalence---or, perhaps, the claim that the sentence in question expresses a proposition, though that seems rather worse. But note that you do not have to abandon bivalence, so to speak, across the board. You might still think that every mathematical proposition is either true or false, or that every proposition about the past is either true or false, or.... Perhaps there is something special about the future here.

As you probably know, Michael Dummett argued that one way to understand debates over "realism" takes them to turn upon our attitude towards bivalence regarding propositions about the subject matter in question: So a view that gave up bivalence for statements about the future would be a form of "anti-realism" about the future.

The general distinction between the two fields is, I think, the same as the relationship between many subjects and the philosophy of those subjects (e.g. science and the philosophy of science), which is that while the subject itself is directly concerned with collating empirical findings and seeking an explanatory framework for those findings, the philosophy of the topic takes a step back and asks about the wider theoretical framework and the support for positing one kind of explanatory framework over another. It asks questions about the nature of the theoretical entities employed and the way in which empirical data is supposed to support or undermine a given account.

In the case of linguistics and philosophy of language, I think this difference in outlook can be seen most clearly in the parts of each discipline which have the most distance from one another. So it's unlikely that many courses on philosophy of language will cover the kind of material on phonetics, intonation, corpus studies, morphology, and sociolinguistics that you'd find in an average lingusitics course. While on the other hand, linguistics courses won't cover the very abstract questions, like 'what is meaning?', which you'll find in philosophy of language, nor will they have much to say about the work of philosophers like Wittgenstein who have had a massive impact on the philosophy of language.

That said, though, there is of course a large area of overlap between the two disciplines. This is especially the case since Chomsky revolutionised the study of syntax in linguistics. Chomsky suggested treating the individual human mind, and the knowledge it unconsciously possessed, as the object of linguistic study, and many philosophers have found Chomsky's overall outlook to be appealing. What this means is that there is a lively area of study at the interface of linguistics and philosophy of language (and philosophy of mind and cognitive science) which deals with the nature of meaning, the divide between semantics and pragmatics, and the nature of communication, and in these debates it can be difficult (and is probably pointless) to try to hold on to too firm a distinction between the disciplines which contribute to the discussion.

I don't quite catch the description given in "indescribable." What positive information is provided? Of course, one might also now wonder precisely what it is we are talking about--because if it is truly indescribable, it sounds like there's not much to say. If so, 'nuff said!

According to my dictionary, the word 'bachelor' means 'an unmarried man'. That's why the statement 'all bachelors are unmarried' is analytic, because the status of being unmarried is built into the meaning of 'bachelor'. Now, when I look up the word 'chair' in my dictionary, it tells me that it is 'a separate seat for one person, of various forms, usually having a back and four legs'. It doesn't define it as 'that which is red', or make any mention of colour at all. Of course, you might very well reply that this is just because it's not actually the case that all chairs are red; and that, if they were all red, the colour would in that case infiltrate the meaning of the word. But I don't buy that. Even if there was a global campaign to paint absolutely every chair in the world red, I still don't feel that the word 'chair' would thereby come to mean 'that which is red'. It would still be defined in the same old way, in terms of an object's form and function. And the reason why I say this is that it seems that the following would still remain true, even in this hypothetical world where all the chairs had as a matter of fact been painted red: if someone was then to paint one of them blue, it would not for that reason cease to be a chair. Even if it were the case that all chairs were red, the universal generalisation, though true, would still be only accidentally true. There are plenty of accidentally true universal generalisations, where everything in a certain category just happens to have a certain property in common, even though it plays no role in the definition of the category. 'All ravens are black', might be an example. 'All swans are white' used to be regarded as one, until they went to Australia and discovered black swans; and the crucial thing to appreciate is that they didn't respond to that discovery by refusing to call these things 'swans': they responded by concluding that the generalisation was false. It's by considering hypothetical scenarios, or actual historical cases like that one, that reveal the difference between necessary, analytic generalisations and contingent, synthetic ones. If a bird was discovered that sufficiently resembled a raven in all the salient ways, but was somehow white, we probably would still say that it was a raven despite that fact -- an albino raven, perhaps, but a raven nevertheless. Even in your world of red chairs, if an object was found which was blue, but which still satisfied the above definition, it would still be called a 'chair'. By contrast, if we meet a man and learn that he is married, we will not call him a 'bachelor'.

Well, there's no short or agreed answer to this question. Not even some kind of a vague consensus. On one end, you have people who think that having once upon a time heard the word "water", and as a result having added it to your vocabulary, is sufficient for competence. On the other end, there are people who think that there is a sense of "complete" or "independent" competence, which is supposed to be the basic sense, on which you have to be able to individuate (distinguish, more or less) water from all other things in order to be competent. This doesn't mean that you in practice have to be able to do this but rather that you know distinguishing characteristics of water. There's another view, too, probably mine, according to which there's no such thing as a "competent speaker". This phrase seems to suggest that there is some norm of competence that some of us meet and some of us do not, and I don't myself know where this norm is supposed to come from. Of course, if one wants to stipulatively introduce some meaning for the phrase, then we can talk about whether that's an interesting notion. But asking whether people understand the word "water", as if it's supposed to be clear what this involves, is hopeless.

For my own part, I'd take the more fundamental question anyway to be what it is to have the (a?) concept water. Obviously, a lot of clarification is needed about what a "concept" is supposed to be, and to some extent, the same range options is available here: more stringent, and more relaxed.

Your question relates to a central issue in philosophy of language concerning the bearers of linguistic meaning: are they objects you can describe formally, like sentences, or much more context-bound entities, like utterances? According to one school of thought, advocated by philosophers like Frege, Carnap, early Wittgenstein and Davidson, meaning should attach to formal linguistic objects, so there is a literal meaning to be recovered for sentences independently of what someone intends to mean or succeeds in conveying when they utter that sentence (for instance, the formalist will claim that 'It is raining' means simply that it is raining even if, on some occasion of utterance, the speaker of the sentence conveys an alternative proposition, like she doesn't want to go outside). On the other hand, many philosophers, like later Wittgenstein, Austin and Searle, have argued that meaning attaches at the primary level to speech acts, so that we really need to know about a context of utterance prior to determining what is meant. Theorists in the second camp are much more sympathetic to the role of context in producing linguistic meaning and are likely to think that interpretation is something which occurs 'on the hoof', as it were. Thus it is likely that people adopting a speech act based approach to meaning would not expect a default interpretation to be the 'literal' or context-free one, rather they would expect that in most contexts what matters is getting at what the speaker is intending to convey by their utterance, while it seems more likely that people adopting a formal approach will maintain the primacy of the literal, context-free interpretation.

However things are made a bit more complicated by recent versions of this debate. Contemporary versions of the formal approach, commonly known as 'minimal semantics', tend to agree with speech act theories that literal sentence meaning is not the default interpretation in most contexts. Instead they allow that what we normally aim to recover in communicative exchanges is what the speaker intended to convey and they recognise that this may often differ greatly from the literal meaning of the sentence uttered. Yet they still maintain that there is a basically context-free level of content attaching at the sentence level and that, when interpreters lack relevant information about the context of utterance, they fall back to this minimal literal content. So, a minimalist would not claim that the default interpretation is the literal one, but they might well say that, where you lack access to the context in which a sentence was produced, all you can recover is the literal meaning so you have to settle for that.

Finally, at least some contemporary versions of the speech act approach (which go under the general heading of 'contextualism') are pretty sceptical about the idea of sentence level literal meaning (at least where this is supposed to be anything like a complete proposition or something which can be evaluated for truth or falsity). So for them when you talk about 'literal meaning', where this refers to the primary proposition a speaker is committed to by their utterance, they will take this item itself to be affected by context. So, for at least some contextualists, the default interpretation might well be the literal one, but the literal one itself is something which can only be recovered only through sensitivity to features of the context of utterance. For such contextualists there might simply be no proposition to be recovered from a 'context-less' writings. So, to answer your question, I think most theorists in the contemporary arena would say that the default interpretation in most contexts of utterance is a 'pragmatic' one, that is getting at the proposition the speaker intended to convey not the one attaching simply to the words she uttered. The debate would then concern whether there is any context-free proposition to be found beneath, or alongside, this pragmatic one and, if so, how it relates to the context-based one (does it provide the inferential base for the context-based one, as some think the philosopher Paul Grice claimed, or is it further removed from communicated propositions, as minimalists claim).

The project of "improving" "the" language is one that has captured the imaginations of many people over time, but it seems to me to be a foolish one to undertake. Let me explain, by explaining my use of scare quotes.

First: "the" language. There's no such thing. If you look at speakers of so-called "English," you'll find that they will differ in their vocabularies, in their grammars, and above all, in the emotional and aesthetic associations they attach to their words. What binds us together is merely the fact that we can to a significant degree understand each other's verbal behavior. But the engines of linguistic change are perpetual motion machines. Slang, idioms, metaphors, abbreviations, invented words -- they all pop in and out of existence, and they're all good. Amidst all this variety, talk of "the" English language is nothing more than abstract idealization -- useful for some scientific purposes, perhaps, but not to be thought of as literally true of human linguistic activity.

Second: "improve". You can't improve a product until you know what function it's supposed to perform. Your suggestion -- that we invent words whose inherent properties resemble the things they refer to -- is presumably intended to improve language's capacity for expressing thoughts. Well, maybe it would, maybe it wouldn't. There's some reason to think that communication goes most smoothly when the referential properties of the linguistic medium are purely conventional -- when nothing about the word itself causes us to linger in thought about the relation betweent the word and the object. But in any case, it looks like people who find need of more evocative connections simply contrive them. That's how "sunny side up" became standard restaurant talk for "fried egg that has not been turned over in the pan." On the other hand, the number of such originally fresh expressions that have become dead metaphors suggests that the pressure of the communicative function causes the erosion of the meaningful associations. I recently overheard a child asking a grownup what he meant by the expression "broken record." And how many people can explain anymore what it is literally to "upstage" someone?

But in any case, language has myriad functions, and improvement in one area need not bring improvement in some other. Furthermore, human beings appear to be extraordinarily resourceful in adapting language to their particular purposes. One of the things language does, for example, is although us to express our understanding of social nuance. Not only do we observe linguistic conventions that encode social relationships -- consider the use of "titles" like "Mr." "Ms." "Dr." -- but we all recognize different norms of verbal expression appropriate to different social circumstances. We use different language when playing with children than when arguing with our mates than when attending a funeral. Moreover, we all recognize that styles change -- new linguistic forms are always developing, and old ones are decaying. Artists who work with language do what artists always do -- they exploit the inherent properties of their medium to create things with aesthetic interest. People interact with other people who speak differently than they do, and pick up some of their expressions. Scientists discover new things, and have to name them. Teenagers need to speak in a way their parents cannot understand. Politicians must contrive new euphemisms to obscure new crimes. With all these means available to use for adapting language to our news, what requires improvement?

It is indeed interesting how we often choose euphemisms when we want to view something in a more positive light, and vice versa. Language certainly plays a significant role in how we think of things, and we ourselves have the power to shape language to a degree by refusing to use certain expressions which we find inaccurate and replacing them with other expressions which are more neutral or even more value-laden. In the United States I suppose the most obvious example is whether one calls someone a terrorist, a militant or a freedom fighter. The news tends to use the middle term, but those more directly involved in a struggle often select one of the other expressions. It would be rather too strong to say that the language here shapes us since we should be aware of how it is being used and what choices we have. An awareness of the power of language is important for philosophers, and all citizens, since an unthinking acquiescence in a certain use of it is highly damaging to us morally and intellectually.