It's the difference between thinking that everything is, ultimately, made out of ideas (what we think of as the physical world is somehow a mental construction) and having ideals (and optimistically thinking that people can and should live up to them).

Why on earth not? Elementary mathematics is full of proofs of negative claims. There are familiar school-room proofs that no negative number has a real square root, that no fraction is the square root of two, that there is no largest prime number.

Wel, fore a starrt, speeling mistaches can mak itt dificcolt two reed & undestand wot u ar actuwally tryin to saye, eh? An getting yours grammer awl rong can makes mawr problem of comprehention. Of course, there are occasions where pointing out slips in spelling or grammar can be a bit rude and pointless. But equally, it is -- to say the least -- impolite not to try to smooth communication by using standard spellings and constructions.

But isn't there an odd tension between saying that you would like to write and take part in the exchange of philosophical ideas and saying that you have no interest in teaching? Isn't teaching In a university (the kind of teaching for which a PhD is required) one sort of exchange of ideas? And isn't it a particularly valuable one for the teachers who are thereby forced to make their ideas as clear and accessible as they can and to respond to the challenges of their students who in turn can teach them so much? How many philosophers can do good work without the constant challenges thrown up in their teaching?

No. There isn't anything intrinsically selfish about sharing fun a deux, whether it is singing duets, riding a tandem, or sex. Of course, the sex-for-fun might be cheating (if you are in a relationship) or unwise (if you don't know where s/he has been) or against professional ethics (if you are a doctor, s/he your patient) or a bad idea for other reasons. But then again, it very likely will be just fine.

Let's agree that, at bottom, a thing's colour is a matter of how it affects us. Still, that rough thought can be sharpened in various ways. As a more careful second shot we might say: something is red if it is such that, in normal lighting, it will produce a certain visual response in normal perceivers. And for present purposes we can leave it open whether the response is best characterised in subjective terms (in terms of a certain look that red things typically have) or in neural terms (in terms of how our retinas and visual systems respond). For note that, either way, if we do analyse the notion of being red as a matter of being such as to produce a certain response in normal perceivers in normal lighting circumstances, it can continue to be such even when e.g. not in normal lighting. Compare: the glass is still fragile even when it is dropped on a cushion and doesn't break, for being fragile is (roughly) a matter of being such as to tend to break when dropped on hard surfaces, etc. The rose is...

Let me add a few remarks, not to disagree with Charles Taliaferro, but to help bring the discussion back to earth after wondering about zombies, etc! I understand quite a bit about my friend Jack's political point of view (we argue often enough in the pub); but I've little idea where he is coming from sexually (what clues I have seem to have no pattern, and a few drunken chats have left me even more mystified). My colleague Jill shares my tastes in music, and we seem to enjoy much the the same concerts and CDs for the same reasons -- when we talk about them, sometimes at length, we seem to be very much on the same wavelength; but in some other respects she's a closed book to me, and the more we discuss, the less I feel that I am "getting" her. And isn't that how it ordinarily is (when we use "understand" in the ordinary way, not in some fanciful philosopher's sense)? We might understand someone's take on X very well, find it difficult to get on their wavelength on Y but sort-of understand, and...

Perhaps it is worth pausing to ask: What is it to "philosophize"? What sort of questions or puzzles or worries call for "philosophizing" as a response? You might say: philosophy is a motley business, embracing Plato's Symposium and Kierkegaard's Works of Love as well as Aristotle's Physics and Frege's Foundations of Arithmetic . We might count too Montaigne's Essays , or Sartre's Nausea . Very different styles of thought, reflected in very different literary forms, but all counting as philosophizing in a broad sense. Or you might say: we really do need a label for a narrower kind of business (which has always been a key department of philosophy in the broader sense), where we aim to investigate fundamental conceptual questions and foundational assumptions with a distinctive kind of rigour and clarity, depending on sharp conceptual distinctions and tight logical argument, and where the preferred literary form is now the academic paper or monograph written in very cool, analytic,...

It is false that Cambridge is a bigger city than Oxford. But that doesn't meant that the statement that Cambridge is a bigger city than Oxford entails a contradiction. It plainly doesn't. We can all imagine a world where history went just a bit differently and Cambridge ended up the bigger city; there's no internal incoherence at all in that counterfactual story, no contradiction is entailed. You might say, sloppily, that the claim that Cambridge is a bigger city than Oxford contradicts how things are (or some such). But contradicting how things are in this sense, i.e. being plain false, doesn't mean being necessarily false, and doesn't mean entailing a constradiction in that sense of "contradiction" in which, arguably, anything follows from a contradiction.

Well, to take the obvious starting point, what about Jane Austen? -- any of her novels you choose, really, other perhaps than Northanger Abbey . 1 My own favourite is Emma, though perhaps her exploration of the virtues (Aristotelian and Christian) is equally near the surface in e.g. Sense and Sensibility and Persuasion. The great tradition of subtle moral reflection in novel form continues in e.g. George Eliot, Henry James, and Edith Wharton. Then of course there are the Russians (longer, yes: but wonderful -- and, for heaven's sake, with such masterpieces to read, don't wastetime on a fourth rate writer like Ayn Rand). What about Crime and Punishment , for another obvious suggestion? And the greatest of all novels -- Anna Karenina -- is shot through and through with reflection on what it is to live well. 1. Incidentally, there's an engaging essay by the philosopher Gilbert Ryle, 'Jane Austen and the Moralists' which is well worth reading (perhaps most...