A chair, or not a chair? That was HG Wells' question:
In co-operation with an intelligent joiner I would undertake to defeat any definition of chair or chairishness that you gave me. — First and Last Things
Running with the idea, Max Black imagined an even more ambitious project:
... an exhibition in some unlikely museum of applied logic of a series of "chairs" differing in quality by least noticeable amounts. At one end of a long line, containing perhaps thousands of exhibits, might be a Chippendale chair: at the other, a small nondescript lump of wood. — Vagueness: an exercise in logical analysis
Such is the now familiar approach of fuzzy logic: instead of the either-or question, ask, "whereabouts is this or that object located on the
chair spectrum"? And this seems in much the same spirit as when we say, "there is no black and white, only
shades of grey".
There is an opposite current of thought: we hear about the dangers of slippery slopes and relativistic thinking, and about the desirability of "zero tolerance" in many areas. But the reality of borderline cases, when faced up to intellectually rather than swept aside dogmatically, tends to leave Black and White looking very much the less well-funded party in its propaganda skirmishes against the Shades of Grey.
I want to support the underdog, and argue that the absolutist intuition that seems, quite often, to separate black from white, in some way that resists deflation of their status and territory to that of extreme greys, is essential to properly understanding human language. The challenge is to be able to look at fuzzy borders head on, but in some way that doesn't result, as is more usual, in us losing our sense of absolutism, and allowing the fuzziness to create a slippery slope from one category (say, black) to another (white). I fancy the way to achieve this is through a technical feature of Nelson Goodman's analysis of 'notationality': a notion closely related to the property known more widely as that of being 'digital'.
"Chair" has no immediate antonym or 'anti-chair': whereas, for example, black has white. Indeed, one suspects that Wells may have chosen it as a case-study precisely for that reason. An adventure of successive expansions for the extension of "chair" doesn't seem headed for any natural denouement. We could perhaps
invent a plausible concept of anti-chair: even by that very name, and exemplified by any (distinctly unhelpful) device designed to stop people sitting down. However, to explain my proposed adaptation of Goodman's principle, it will be just as feasible for me to square up to Wells' teasing example of,
chairs that pass into benches, chairs that cross the boundary and become settees
Wells is quite right that he and his joiner might realistically hope to so influence usage that any sense of mutual repulsion between the extensions of "chair" and "bench", or even between those of "chair" and "settee", were significantly reduced. Not that there wouldn't remain enough underlying tension to distinguish the extensions: there might well be examples of each category that were certainly not examples of the other; just that there would be an overlap. Objects that were both.
But we can equally well imagine a usage becoming entrenched, even if only or mostly within the furniture trade, according to which there is reliably no overlap, and being able to call something a chair is sufficient to imply that it isn't a settee, and vice versa. Specifically, and adapting Goodman's notation-based principle, calling something a chair (within the limited specified discourse) then indicates zero probability of it ever (within the discourse) being called a settee. To someone who protests, like Humpty Dumpty, that they can point a word at whatever they like, we simply insist that they are not speaking the specified language: where 'language' is to be glossed as 'discourse' or 'interpreted language' or 'language in use', to clarify that competence with meaning as well as syntax is assumed. In the present example the discourse is relatively circumscribed, and particular to the furniture trade, but the principle scales up: as where we can for example comfortably deny that someone may, within the larger English language as spoken and interpreted literally, succeed in pointing the word "black" at white. (Or point the word "chair" at a device for preventing sitting.)
This way, the borderline examples of "chair" that we, as speakers, actually dispute and agonise over are far from the similarly borderline cases of "settee" but are our present best data about the whereabouts, on a gradual scale like Black's, of the edge of the
possible extension of "settee". This is because the borderline cases that we dispute and negotiate are ones that are on or near the border of current data or samples of use, not the border of the background population or theoretical 'support'. However, with antonyms or with discrete categories in a conceptual scheme, as also with any two distinct characters in a syntactic alphabet, being in one means definitely not being in the other. So 'data' about the one limits the theoretical reach of the other. So 'chair' means 'definite non-settee' and 'settee' means 'definite non-chair'.
Assuming that reference (what I've called 'pointing') isn't a matter of fact (is '
inscrutable'), then neither is the background population nor the foreground sample of acts of reference (pointings). But agonising over borderline cases is how we maintain the fiction in such a way that it keeps discrete categories discrete. Agonising and allowing disputes over borderline cases of, say, "chair" (=> "definite non-settee") and of "settee" (=> "definite non-chair") causes the 'actual' extension of each - its 'observed' incidence of usage - to thin out to nothing well clear of that of the other. The fuzzy border where an object may be variously judged "chair" and "non-chair" is kept well away from the fuzzy border where objects are judged both "settee" and "non-settee".
Example.