Date: Wed, 23 Jul 2008 02:23:04 -0700 (PDT)
On Jul 23, 5:44 am, "Brian Selzer" <br..._at_selzer-software.com> wrote:
> "JOG" <j..._at_cs.nott.ac.uk> wrote in message
> > On Jul 22, 2:44 pm, "Brian Selzer" <br..._at_selzer-software.com> wrote:
> >> "JOG" <j..._at_cs.nott.ac.uk> wrote in message
> >> [big snip]
> >> >> I contend that there is a difference between a symbol that represents
> >> >> something in the universe and a value. If that runs counter to your
> >> >> particular brand of common-sense, then I sympathize but suggest you
> >> >> adopt
> >> >> another.
> >> > Yes, we know that. But you're value = object definition leads to the
> >> > contradictions:
> >> I think I should clarify this a bit. I'm probably going to botch this,
> >> so
> >> please bear with me.
> >> A value is not just an object, but rather the image of
> >> an object: within the picture of the universe that is under
> >> interpretation,
> >> the value /is/ the object,
> > There is no such thing as an image of an object. Different view of the
> > world. Different objects altogether. RM is implicitly underpinned by
> > this principal and hence its lack of row identifiers and use of keys
> > (and again this accords with everyday evidence of how we refer to the
> > world). It seems like you are still resolutely avoiding accepting this
> > one - but hell, plato got this sort of thing completely wrong too so I
> > guess at least you're in famous company (...although we do have 2
> > millenia of combined knowledge on him now).
> I'm going to tell a story now, and as the story progresses, you'll find that
> there are indeed images of objects, because the state of the universe at the
> beginning of the story is not the state of the universe at the end of the
> A child was born in New York City on January 15, 1964 to Robert and Mary
> Smith. The child was named John for Robert's grandfather, though they
> considered naming him Michael for Mary's grandfather. The happy couple
> imagined how their son would grow up to be a doctor or a lawyer-- how he
> would marry and have children of his own. Little did they know that he
> would die in an automobile accident before he reached his eigth birthday.
> At the beginning of the story, John hasn't been born yet. There is no child
> object, although the possibility exists that a child will be born.
> Immediately after he his born, the child has yet to be named. While the
> story says that he was named John, at this point in time the child might
> just as easily be named Michael for Mary's grandfather instead. So while
> the possibility exists that the child will be named John, an equal
> possibility exists for the child to be named Michael. Now there are two
> pictures of the universe, the first before the child was born, the second
> after the child was born but before the child is named. After John is named
> and a third picture emerges, his parents imagine several futures for him:
> one where he is a doctor; one where he is a lawyer; one where he has
> children of his own. But the tragic picture of the universe at the end
> denies those futures, and eliminates those possibilities. Clearly the
> picture of the universe that depicts John dead in an automobile accident
> contains an image of John that differs not only from the image at his naming
> but also from the images imagined by his parents-
> even though the child object appears in each of those pictures.
What you describe is no evidence whatsoever of "images of objects". This is important as it may help your views concerning some need for row identifiers. Your story describes not one thing, but at least 4 objects: A life, an unnamed person, a named person and a deceased person all with different properties. There is no one single child object in your story at all. And just because those things overlap doesn't make one any more important than another.
> >> but not necessarily in every picture of the
> >> universe.
> >> > * databases then have no values in them.
> >> Isn't it simpler to say, "I stopped the car." instead of "I applied the
> >> brakes until the car stopped moving." even though you obviously didn't
> >> push
> >> your feet against the ground like Fred Flintstone?
> >> Isn't it simpler in the same way to say, "Databases contain values."
> >> rather
> >> than "Databases contain symbols and combinations of symbols that under an
> >> interpretation map to objects in the universe." even though it is less
> >> precise?
> > A symbol is already defined as "something used for or regarded as
> > representing something else".
> Yet symbols are not values.
> >> > * to tell someone to enter a value into a spreadsheet cell becomes a
> >> > nonsense.
> >> see above.
> >> > * a mathematical formalism contains no values at all, given it need
> >> > not refer to anything in the real world.
> >> What a symbol maps to need not be spatiotemporally located.
> >> > * etc.
> >> > This is all counter to everyday experience, and nothing to do with my
> >> > common sense. It is just not good enough to ignore the actual use of a
> >> > word.
> >> I don't think it is. The context of this discussion demands a level of
> >> precision that is not required in the contexts you cited.
> > Noone needs an imaginary concept of "images of objects", and so we
> > equally don't need some curveball redefinition of "value" by which to
> > refer to them.
> It is not an imaginary concept. A proposition paints a picture of the world
> (under an interpretation, of course). The elements of that picture are
> images or projections of what is in the world. Values.
As I said, this is just the same "shadows on a wall" nonsense the dogmatic hand-waving philosophers of 2000 years ago espoused. Humans define what objects are, they don't simply "exist" pre-packaged (the universe is there of course, but it is us that delineates it into objects). Taking your standpoint just leads to infamous paradoxes of identity, while mine never hits any such contradictions (and as such also generates good database design, which is the only reason I care about it).
I will have to bow out because trying to explain this to you on usenet will be too frustrating and I'll lose my rag...at some point in the near future I'll link you to appropriate papers. Regards, J.
> >> A proposition is
> >> just a collection of symbols combined according to some grammar that can
> >> be
> >> assigned a truth value. Neither the proposition nor the symbols and
> >> combinations of symbols contained within convey meaning until under an
> >> interpretation a truth value has been assigned. A database is just a
> >> proposition that is supposed to be true, but supposing a particular truth
> >> value is not the same as assigning that truth value. As a consequence, a
> >> database is just a collection of symbols combined according to some
> >> grammar
> >> that can be assigned a truth value. It only becomes a collection of
> >> values
> >> under an interpretation as that truth value is assigned.
> > Yes but the point is that you've just made all this up, and it is
> > nothing like how anyone else uses the term. As yet another example
> > consider the output of a mathematical function. It is unarguably a
> > value whether it is interpreted or not.
> I didn't just make this up. Codd equated "datum" with "atomic value."
> Isn't data just information in a form that can be transmitted digitally?
> Information is what is being conveyed during transmission: it is what the
> transmission /means/.
> The output of a mathematical function is a member of a set. That set--the
> range of the function--is the universe with respect to that function. But
> that universe is constant--there can only ever be one picture of that
> universe, so in the picture of that universe under /any/ interpretation, the
> value /is/ the object.
Received on Wed Jul 23 2008 - 11:23:04 CEST