From LOJBAN%CUVMB.BITNET@UGA.CC.UGA.EDU Fri Jul 15 13:04:16 1994 Message-Id: <199407151704.AB25206@nfs1.digex.net> Date: Fri Jul 15 13:04:16 1994 Reply-To: jorge@PHYAST.PITT.EDU Sender: Lojban list From: Jorge Llambias Subject: Re: cukta X-To: lojban@cuvmb.cc.columbia.edu To: Bob LeChevalier Status: RO > From dave@VFL.Paramax.COM Fri Jul 15 10:45:28 1994 > To: jorge@phyast.pitt.edu > Subject: Re: cukta (Dave, I think you meant to send this to the list, so I post your whole message. The default setting for replies is to the original sender, rather than to the list.) > > > Bob Slaughter: > >> > >> I just noticed that we may be confusing *semantic* truth with logical > >> truth. > >> > >> The statement "I am a Klingon" is *logically* true, because it is > >> gramatically properly formed, hence semantic input (wherther I am a > >> Klingon or not) gives meaningful output. > > Since you say the book you read this in is currently packed away, I > suggest that you are misremembering the terminology, or that the author > did not manage to make his point very clearly. Check it out when you > unpack the book. > > > Jorge: > > > > I would prefer to say that it is logically valid, rather than true, but the > > idea is the same. This is related to Colin's +/-features. If there is a > > conflict, then the statement fails logically, and asking about its semantic > > truth is almost meaningless. > > Logicians argue as much as anyone, but there is nevertheless a fairly > wide consensus on basic terminology. > > "I am a Klingon" is *well-formed*, because it is possible meaningfully > to assign a truth value to it. It is NOT, however, "xxxx-true" for > any xxxx that I have ever heard of. (Actually, "well-formed" applies > to statements already cast in logical terms; it is something of an > extension of the meaning of "well-formed" to apply it to a natural-language > statement, to claim that the statement can in fact be turned into a > well-formed formula in the predicate calculus.) > > "I am a Klingon; All Klingons are ugly; therefore, I am ugly" is a > *valid* logical argument. The concept of validity applies to > arguments, not statements. > > --dave > That sounds right. I think what I was trying to say has nothing much to do with logic, in fact. I don't know if *well-formed* is the best way to put it, but this is what I meant: The lojban sentence {mi cusku li mu} is grammatical, but fails in the category matching. It doesn't mean "I say 'five'". That would be {mi cusku zo mu}. As far as I understand, it is a meaningless sentence, although grammatical, so to say that it is true or false is also meaningless. I don't know if we could say that it's *ill-formed*, but there's definitely something wrong with it. Jorge