From @uga.cc.uga.edu:lojban@cuvmb.bitnet Thu Jun 22 23:28:37 1995 Received: from punt2.demon.co.uk by stryx.demon.co.uk with SMTP id AA3542 ; Thu, 22 Jun 95 23:28:33 BST Received: from punt2.demon.co.uk via puntmail for ia@stryx.demon.co.uk; Thu, 22 Jun 95 03:30:37 GMT Received: from uga.cc.uga.edu by punt2.demon.co.uk id aa27591; 22 Jun 95 4:29 +0100 Received: from UGA.CC.UGA.EDU by uga.cc.uga.edu (IBM VM SMTP V2R2) with BSMTP id 4972; Wed, 21 Jun 95 23:27:41 EDT Received: from UGA.CC.UGA.EDU (NJE origin LISTSERV@UGA) by UGA.CC.UGA.EDU (LMail V1.2a/1.8a) with BSMTP id 4971; Wed, 21 Jun 1995 22:35:54 -0400 Date: Wed, 21 Jun 1995 15:53:39 -0700 Reply-To: "John E. Clifford" Sender: Lojban list From: "John E. Clifford" Subject: pc answers X-To: lojban list To: Iain Alexander Message-ID: <9506220429.aa27591@punt2.demon.co.uk> Status: R To wander somewhat off the point, I have noted that in logic quantifiers and descriptors have little to do with one another. They are grammatically quite distinct (in most systems) and they perform quite different functions. Descriptors *refer* to things, stand for them directly or only moderately intermediated. Quantifiers *range over* things, make metalinguistic remarks about whatever refers to them but refers to them not at all. Descriptors are at most two linguistic levels removed from the world, quantifiers are at least four levels out and rely heavily (in most systems, essentially) on the directly referring expressions. Descriptors are concrete, unique, precise; quantifiers are abstract, general, vague. The nearest they come to contact one another is that sometimes they systematically can be used to make claims that define exactly the same logical situations. I have been trying to explore some cases in which the situation described using some descriptor from Lojban could be expressed using the quantifiers of logic. I did not mean this to suggest that the descriptors of Lojban *are* logical quantifiers. But now I am told that it is built into Lojban that each descriptor *means* some quantifier expression. As a logician, I hope that this is not true, since it would mean that the "logical language" was ultimately not only illogical but unusable. If all descriptors are just quantifiers, then we have no way to refer to objects in their absence. When they are present we can point to them with the deictors, _ti_ and _do_ and the like, and we can adress them, if they have names, _coi_djan_. But we cannot refer to them, only say some general claim, which, if we are lucky, will happen to be true just in case those ineffable things do so and so, but which will not mention those things at all. Even the person I just called djan to his face becomes merely "there is an x which I have in mind to call djan such that" when I try to talk about him. Even fundamental logical operations, like instantiation or generalization become rather transformations of gneralizations, since there are no instances to get to or from. Something seems seriously wrong here. But the quantifier=descriptor system as it is laid out is also incoherent. We are told that _ci_gerku_ just is _ci_lo_gerku_, which just is _ci_lo_so'u_gerku_. From which we can infer that that just is _ci_lo_so'u_lo_gerku_ which just is _ci_lo_so'u_lo_so'u_gerku_. And so on. And, in the other direction, _ro_lo_ci_lo_nanmu_ just is ultimately _ro_ci_nanmu_, which, if not ungrammatical, is at least not very sensible. And if that is not wrong, what about _roda_poi_cide_poi_nanmu_ (or even _cida_), which is also what the original expression is said to just be? I take it that those special cases where quantifiers and descriptors can be used to describe the same situation in fairly obviously related ways have been generalized to the claim that correspondingly parallel sentences involving the two types of expressions will always describe the same situations. And this is now thought not to be a lucky break but a part of the *meaning* of the expressions. It is not even obvious that it works at all (part of the reason for the investigation of which this is a digression) and, if it does, it really is a lucky break, since, as noted, it is not a part of meaning. Of course, if it does work, it will not be a lucky break at all but rather the result of a fiat by the creators of the language and, hopefully, one that will be made with full awareness of what is being done. pc>|83