Nice article, marred by the inaccurate presentation of maternal-fetal immune reaction. Most severe allergic reactions to the child have to do with Rhesus type, not ABO type. ABO reactions are rarely serious, and could only occur in a type O mother, because it's type Os who have the anti-A and anti-B antibodies in their blood serum. Irrelevant sidenote: they made a similar mistake on 'House' recently.
Much of this discussion seems to be taking place within a somewhat naive conception of language and representation; in particular, it seems to me to be neglecting the insights that structuralism provided, overapplied though they may at some points have been. Contemporary linguistics, and much though sadly not all contemporary philosophy, recognise that language and thought operate both through the binding of words to images and then to 'things', and through distinguishing things and locating them within articulated systems. You can't have pointing, to give the example of a seemingly basic form of 'reference', without a system that distinguishes pointing-gestures from other motions of the hand, that defines the range of motions that count as pointing-gestures etc. I'm not going to get into a comment war about it, because there simply isn't space here, nor do I have the time, to have the sort of sustained argument that would be necessary to 'prove' this to someone used to thinking about language in another way - I can only recommmend more reading. Wittgenstein of course discusses this in the 'Philosophical Investigations', but - and I know I'm going to lose 90% of you when I say this, yet here you are anyway: one of the most lucid articulations of this double aspect of cognition occurs within psychoanalytic theory. I'm reading a very interesting book, 'Freud as Philosopher' by Richard Boothby, at the moment which I'm finding to be a particularly good treatment of this. To Eliezer in particular, I can't recommend this strongly enough - he provides a reading of Freud that's very different to the 'folk' one, and so far I particularly like his discussion of the relation of gestalt perception to the experience of mental imagery. Since we're discussing our personal experiences, it came as a real surprise to me when I realised that some people couldn't hear the rhythm of words in their heads - having to count out the syllables of an iambic pentameter, for example. Another dimension I think it's interesting to consider here is imagining abstract concepts kinaesthetically. When I visualise the concept 'status quo bias', to use Roko's example, I imagine being subject to a force - a little like gravity, but stronger, maybe something like the feeling of holding a strong magnet away from something it's attracted to. I'm sure this is a heuristic that helps me to think more fluidly and intuitively about the concept.