From Pycyn@xxx.xxx Mon Dec 20 11:43:32 1999 X-Digest-Num: 316 Message-ID: <44114.316.1742.959273825@eGroups.com> Date: Mon, 20 Dec 1999 14:43:32 EST From: Pycyn@xxx.xxx Subject: Re & on ? I pretty much agree with & on the details of the intensional context in which "Pegasus was the winged horse captured by Bellerophon" is embedded. My point is only that we do not need all the details usually, but we do sometimes need a reminder that it IS in an intensional context, that substitutivity and quantification do not work in normal ways. Hooha and, in this case, ku'a were meant to handle the minimal needs, between the contextual and the fully explicit. As for the sense of names, I have to admit that that shot is used as a quick stopper, which usually works but did not this time. In fact, names do have senses, even in Frege (though he keeps very quiet about it), since reference in intensional context is to senses rather than usual references. Just what the senses are is tricky but appear at first glance to be just "is named ...," since that accounts for the general failure of substitution. It won't quite work, however, since the sense is what picks out an individual in a possible world and many possible worlds have that individual with a different name (and gender and species and...). Of course, it could be argued that the sense of the name was different from the individual concept of the referent of that name and thus the above problem did not arise. Semantics is not always decisive, even after a century and a quarter on these issues. That still does not mean that names are predicates, since that would still give the referent of a name as a class rather than an individual (Quinean magic being discounted here, as usual). The arguments that names behave like predicates in English seem to rely heavily on constructions with "the," a notoriously polysemic -- and polytactic -- word (witness the complexities of Lojban's attempts to capture, which still leave a residue of cases), and on cases of the English pattern of using nouns in modifier positions (adjectival) -- though most proper names seem to require some modification to work smoothly here. And, of course, English evidence is not decisive in questions of logic. "For x=Paul," is a perfectly good quantifier in a Montagovian sense. It is a restricted quantifier, of course, and Lojban has resisted that notion pretty strongly -- at least the existential commitment part. In any case, it amounts merely to setting a value for a term that inherently can take on a variety of values. I suppose that it is equivalent to Ex (x = Paul &...x...) but is more compact. It is not Ax(if x = Paul, then ...x...) because it does insist that Paul exists (the restricted quantifier again). Which brings us back to the reading of names as "For all x, if x is-Paul, then ..x..)" and the problem of deriving "for some x,..x..) from such sentences. As noted, ifwe use this to deal with "Pegasus was a winged horse" to prevent the inference to "There was a winged horse," then we cannot get an existential generalizations from names at all. If, as & insists, there is a way to do it with "John F. Kennedy" and "argon" (a slightly iffy case), then surely the same trick will work with "Pegasus" UNLESS the "Pegasus" sentence is marked as in an intensional context and the others are not. That was the only point of the example. But note, & still owes us an explanation of how to get from "for all x, if x = [name] then ..x.." to "for some x...x.." I suspect that the trick here is just that extensional names all have referents and so "for some x, x = [name]" is an axiom to be used in the (enthymemic) inference. But then, why not just take names as terms that can be generalized on (and universally instantiated to -- I'm not so sure how to fill out &'s enthymemic version of this one) from the start -- if we are careful about context. (Or we might just take all these Ax=> locutions as historically misidentified restricted quantifiers - many of them are -- and work with the original quantifier rules, in Aristotle, with some help from Chrysippus.) The discussion with xorxes reminds us yet again that we can't do everything with quantifiers and connectives, that there are pragmatic considerations that remain even when we max out on precision. To be sure, it would be nice to be able to mark these as well, but we only have a finite set of words to work with. pc