Better: There's a fairly simple proof that this is false. Just consider the theory consisting of the sentence letters p1, p2, .... This theory is clearly consistent. It'd be an amusing question just how easy the proof is, i.e., exactly what sorts of theories are needed for the proof.

What I'd "make of the idea that philosophers are trying tounderstand the world through natural language, and not through enoughof an observational component, and method" is that this generalization is just plain false. Philosophers throughout history have drawn upon science, mathematics, literature, art, theology, and whatever else they can get their hands on in an attempt to deal with the questions that perplex them. Once philosophers have achieved enough of an understanding of a question to make it susceptible to serious scientific investigation, what happens is, well, that the question starts to receive serious scientific investigation, and at that point its no longer a question for philosophers but a question for some often new branch of empirical science. This has happened time and again throughout history. So philosophers often aren't in the business of answering questions but rather in the business of clarifying questions: clarifying them enough that empirical work can then be done. As...

It isn't entirely obvious that I, say, could have been female from conception, and the assumption that the fertilizing sperm was different certainly leaves that possibility open. But if I could have been female, then your great-great-great grandfather (let's say) could have been female, and one of your great-great grandwhatever's parents would have had a hard time conceiving a child together. Maybe that isn't the sort of possibility you had in mind. But it's not obvious how to restrict it and still get plausible results. Let's suppose you could have been the result of fertilization by a different sperm. What's so special about the sperm? Why not a different ovum, too? But now consider that other ovum and sperm. The latter could have fertilized the former even if the ovum and sperm from which you were actually formed still got together. But then are you your own twin? I don't think so. So it doesn't look as if you could have been the product of a different ovum and a different sperm. But if not, then...

Where is it written that what is 'natural' is morally acceptable? Unless some argument is offered for this claim, there is a blatant non sequitur in these remarks.

Yes. There is a book, Wittgenstein and Buddhism , written by Chris Gudmunsen. That's all I know about, but there is probably much more.

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...

Perhaps the first question worth answering would be what one means here by "natural". What is "natural" can be opposed to many different things: "artificial" might be one, for example, but that doesn't seem to be quite what one has in mind when one asks whether homosexuality is "natural". Indeed, I'm inclined to think you don't know very well yourself what you mean by the word: hence all the "scare quotes". Another question is why it should matter. If homosexuality is not "natural", does that mean it must be wrong? One might well suggest, and it has indeed been suggested, that sex with birth control is not "natural" either, but, despite the wel-known views of some, many of us wouldn't infer anything about the moral status of such expressions of sexuality from the fact, even if it is one, that it is not "natural". And sure, there are plenty of senses in which men and women are "complementary". Among them, the obvious one is that it takes a man and a woman to make a child. But it's hard to see what's...

To ask a question our illustrious leader, Alexander George, has several times asked here: What's meant by "prove"? If what's meant is what's ordinarily meant by "prove", then it's not clear that a single person on this planet can prove human beings evolved from apes. Nor can anyone prove that the Loch Ness monster does not exist. But that simply doesn't mean that there can't be good reasons to believe that human beings evolved from apes or that the Loch Ness monster does not exist. There can be, and there are. Now what exactly that has to do with the rest of the question is not yet clear. But have a look here http://plato.stanford.edu/entries/pascal-wager/ for some thoughts (not mine).

At the time the questioner mentions, it wasn't just religious claims that philosophers declared "cognitively meaningless". Any metaphysical claim was supposed to suffer the same fate. Well, part of what's changed is that that's changed. Metaphysics is now a flourishing, and for the most part respectable, branch of philosophy again. So while it may be hard to be sure quite what "God is the Supreme Spirit, Who alone exists of Himself and is infinite in all perfections" means, it's surely not much harder than to be sure what (-- insert quotation from contemporary metaphysician --) means. The idea that some things exist in and of themselves and that some things exist only in virtue of the existence of other things, in particular, is quite metaphysically respectable: For example, pretty much everyone would agree that a set exists only in virtue of the existence of its members. Of course, it's one thing whether flat-footed interpretations of religious claims would render them meaningless. It's...

What is the purpose of this "debate"? Is there a trophy? a financial reward? Or is the purpose supposed to be to determine the truth? or to determine what we should believe? I think the answer to your question very much depends upon the answer to this question. Let's suppose the purpose of the debate is to determine what one should rationally believe. What who should rationally believe? Does the person already have a view on this question? That is: Is she already a believer or a non-believer? Or is he or she utterly agnostic? This question, too, matters, at least according to some epistemologists, since these philosophers would take seriously the idea that the question we thinkers face is always whether to change our existing beliefs. And there's another crucial question, at least on some religious epistemologies: If one bases one's belief upon religious experience, how is that supposed to enter the debate?