The Virgin Birth of Points
in [Physics]
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From: Wolf Kirchmeir on 6 Dec 2007 19:46 Shrew_D wrote: > On Thu, 06 Dec 2007 14:29:27 -0500, Wolf Kirchmeir > <ElLoboViejo(a)RuddyMoss.com> wrote: [...] >> See, when you talk about term you are not talking about what they refer >> to. Eg, We had a cat named Alex. Now "Alex" is a Greek name. When I say >> that, I'm not talking about Alex-the-cat. We also had a friend named >> Alex, so we had to be sure we knew which Alex "Alex" referred. Context >> was usually enough for that. Terms are not the things refer to. >> Definitions restrict what terms refer to, but a definition says nothing >> about whether the referent actually exists. IOW, when I told you above >> you that "Alex" referred to my cat, you couldn't know whether I actually >> had a cat named Alex. Or whether I had a fiend named Alex. See? > > A few well placed predicates in the definition might clear that up. Now I don't think you know what predicate is. Just what do you think you mean by 'predicate'? > And as mentioned previously definitions can't say whether a thing > exists, but they can say whether a thing can't exist. Good grief, Shrew: can't you see that "X does not exist" is an existence claim???? It doesn't matter whether you claim X does or does not exist, either way you've made a claim about X's existence. So, if you claim that a definition can say that X can not exist, a definition must perforce be able to say that X can exist. You can't have one without the other. But the definition cannot decide that. > As for you and > your "fiends" I'll leave you to them. We needn't belabor the obvious > further. Yeah, I caught that typo too late. Soy about that. HTH
From: Shrew_D on 7 Dec 2007 13:34 On Thu, 06 Dec 2007 19:39:38 -0500, Wolf Kirchmeir <ElLoboViejo(a)RuddyMoss.com> wrote: >> I didn't comment on what Lester means by predicates. I commented on >> what Lester said when Randy neglects to say when he defines definition >> as just shorthand. > >Yeah, but Lester used 'predicates' in his comment. Yes and I've used the term myself. Doesn't alter the fact that Randy claimed definitions are "just shorthand" without explaining what definitions are shorthand for. If Randy had something significant to say on the subject he could have used another word.
From: Shrew_D on 7 Dec 2007 13:51 On Thu, 06 Dec 2007 19:46:09 -0500, Wolf Kirchmeir <ElLoboViejo(a)RuddyMoss.com> wrote: >Shrew_D wrote: >> On Thu, 06 Dec 2007 14:29:27 -0500, Wolf Kirchmeir >> <ElLoboViejo(a)RuddyMoss.com> wrote: >[...] > >>> See, when you talk about term you are not talking about what they refer >>> to. Eg, We had a cat named Alex. Now "Alex" is a Greek name. When I say >>> that, I'm not talking about Alex-the-cat. We also had a friend named >>> Alex, so we had to be sure we knew which Alex "Alex" referred. Context >>> was usually enough for that. Terms are not the things refer to. >>> Definitions restrict what terms refer to, but a definition says nothing >>> about whether the referent actually exists. IOW, when I told you above >>> you that "Alex" referred to my cat, you couldn't know whether I actually >>> had a cat named Alex. Or whether I had a fiend named Alex. See? >> >> A few well placed predicates in the definition might clear that up. > >Now I don't think you know what predicate is. Just what do you think you >mean by 'predicate'? I'm not sure anyone knows exactly what a predicate is. I use the word to indicate something predicated of something as I explained a few posts ago. I'm surprized you don't remember and begin to wonder just how assiduously you read my comments. >> And as mentioned previously definitions can't say whether a thing >> exists, but they can say whether a thing can't exist. > >Good grief, Shrew: can't you see that "X does not exist" is an existence >claim???? It doesn't matter whether you claim X does or does not exist, >either way you've made a claim about X's existence. So, if you claim >that a definition can say that X can not exist, a definition must >perforce be able to say that X can exist. You can't have one without the >other. But the definition cannot decide that. Naturally it can unless you suggest a self contradictory definition is not false and thus the thing defined does not exist. Or you might just say a thing is self contradictory according to its definition and let it go at that. However I don't see the inference of self contradiction and false and non existence is that great a leap to make especially since exactly the same standard of false is used in propositions. >> As for you and >> your "fiends" I'll leave you to them. We needn't belabor the obvious >> further. > >Yeah, I caught that typo too late. Soy about that. I've often wondered why Asians and so many others insist on white rice when they just have to doctor it up with soy and hot sauce to give it nutritional value and taste like something besides cardboard.
From: Shrew_D on 8 Dec 2007 00:28 On Fri, 7 Dec 2007 11:30:20 -0800 (PST), Randy Poe <poespam-trap(a)yahoo.com> wrote: >On Dec 7, 1:51 pm, Shrew_D <Shre...(a)paleo.net> wrote: >> On Thu, 06 Dec 2007 19:46:09 -0500, Wolf Kirchmeir >> >> >> >> <ElLoboVi...(a)RuddyMoss.com> wrote: >> >Shrew_D wrote: >> >> On Thu, 06 Dec 2007 14:29:27 -0500, Wolf Kirchmeir >> >> <ElLoboVi...(a)RuddyMoss.com> wrote: >> >[...] >> >> >>> See, when you talk about term you are not talking about what they refer >> >>> to. Eg, We had a cat named Alex. Now "Alex" is a Greek name. When I say >> >>> that, I'm not talking about Alex-the-cat. We also had a friend named >> >>> Alex, so we had to be sure we knew which Alex "Alex" referred. Context >> >>> was usually enough for that. Terms are not the things refer to. >> >>> Definitions restrict what terms refer to, but a definition says nothing >> >>> about whether the referent actually exists. IOW, when I told you above >> >>> you that "Alex" referred to my cat, you couldn't know whether I actually >> >>> had a cat named Alex. Or whether I had a fiend named Alex. See? >> >> >> A few well placed predicates in the definition might clear that up. >> >> >Now I don't think you know what predicate is. Just what do you think you >> >mean by 'predicate'? >> >> I'm not sure anyone knows exactly what a predicate is. > >If that were true, it would really be silly to claim >that any particular set of words constituted one, >wouldn't it? No. >However, it's not true. "Predicate" has a specific meaning >in logic, which I presume is what we're discussing. I don't know what you're discussing. >As it happens, that meaning is not what I thought it >was. What I was calling a "predicate" seems to be >a "proposition". Here is the actual definition: Oh dear. So you were mistaken but now you're the authority? >http://www.cs.odu.edu/~toida/nerzic/content/logic/pred_logic/predicate/pred_intro.html > >"A predicate is a verb phrase template that describes >a property of objects, or a relationship among objects >represented by the variables." > >Examples from that page: "is blue" > "gives x to y" > >http://en.wikipedia.org/wiki/Predicate_%28logic%29 >"In formal semantics a predicate is an expression of >the semantic type of sets. An equivalent formulation >is that they are thought of as indicator functions of >sets, i.e. functions from an entity to a truth value." > >"In first-order logic, a predicate can take the role >as either a property or a relation between entities." > >http://rbjones.com/rbjpub/logic/log019.htm >"Predicates (or relations): > > * Are operators which yield atomic sentences. > * Operate on things other than sentences. > * Are therefore not truth functional operators. > * Yield atomic sentences whose truth can be determined > knowing only the identity of the things to which > the predicate is applied (i.e. they are extensional)." > >I found these by searching for "predicate logic". Since >there is such a thing and every text on logic defines >predicate, it's a little silly to claim that nobody >has ever seen or written a definition for "predicate". I didn't claim that. >Getting back to the Zick example, "square circle" >is clearly not a predicate. However, "is square" >is a predicate, and so is "is circular". These >are properties that operate on objects, that >can be written in the form "P(x)" meaning >"x is square" for example. > >The definition "A squircle is a square circle" >also fails to meet these tests. So in the phrase "a squircle is a square circle" nothing is predicated of a "squircle"? > All it does >is rename "square circle" as "squircle", establish >a substitution code. And so with any definition. So if "is square" and "is circular" are predicates, "is a circular square" is not a predicate?
From: Shrew_D on 8 Dec 2007 00:30
On Fri, 7 Dec 2007 09:55:58 -0800 (PST), stephenkwagner(a)gmail.com wrote: >On Dec 6, 6:46 pm, Shrew_D <Shre...(a)paleo.net> wrote: >> On Thu, 6 Dec 2007 09:21:35 -0800 (PST), stephenkwag...(a)gmail.com >> wrote: >> >> >> >> >On Dec 6, 11:52 am, Shrew_D <Shre...(a)paleo.net> wrote: >> >> On Wed, 05 Dec 2007 22:33:18 -0500, Wolf Kirchmeir >> >> >> <ElLoboVi...(a)RuddyMoss.com> wrote: >> >> >> However I think my original point regarding Randy's use of "short- >> >> >> hand" still stands because clearly the "shorthand" in a definition has >> >> >> to be "shorthand" for something and I thinkLesteris correct on this >> >> >> issue. >> >> >> >Since I cannot figure out whatLestermeans by "predicates" etc, I can >> >> >neither agree nor disagree. >> >> >> You can't agree that "shorthand" means "shorthand for something"? >> >> >What is your point? >> >> >A definition is shorthand. >> >> Shorthand for what? > >Did you really not understand the example? > >> >> >If I define 'regular graph' to be 'a graph in which all vertices have >> >the same degree', >> >then the phrase 'regular graph' is shorthand for the phrase 'a graph >> >in which all vertices have the same degree'. >> >> Then a definition is certainly more than merely shorthand because it >> includes the phrase for which the shorthand stands. > > >> >> > Anywhere the phrase >> >'regular graph' appears, you can replace it with the phrase 'a graph >> >in which all vertices have the same degree'. >> >> Except adherents of the shorthand theory for the definition of >> definition assure us definition is "just shorthand", which is plainly >> absurd since it is the phrase to which the shorthand corresponds which >> is the definition and not just the shorthand. >> >> >In what sense do you not know "the something" the short hand is for? >> >> In the same sense as proponents of the "just shorthand" definition of >> definition neglect to include what the shorthand is shorthand for in >> defining definition. > >At this point you seem to be trying to purposefully misunderstand. >If so, then you will just love Lester. > >'Adherents of the shorthand theory' know exactly what the purpose >and nature of definitions are, and they know that when they define >a regular graph as a graph in which every vertex has the same degree, >then all they are saying is that 'regular graph' is shorthand for >'a graph in which every vertex has the same degree'. > >Do you really not understand that? Actually I really do understand that. It's Randy who doesn't really seem to understand that there is more to a definition than shorthand. |