Re: the two questions

On Nov 30, 3:46 pm, "Brian Selzer" <br..._at_selzer-software.com> wrote:
> "JOG" <j..._at_cs.nott.ac.uk> wrote in message
>
> news:55517bf1-c48a-4bdf-9e84-6d72f81aca83_at_y43g2000hsy.googlegroups.com...
>
>
>
> > On Nov 28, 1:07 pm, "Brian Selzer" <br..._at_selzer-software.com> wrote:
> >> "JOG" <j..._at_cs.nott.ac.uk> wrote in message
>
> >>news:0c832d02-88f5-495c-ab2b-8098afcd8818_at_d21g2000prf.googlegroups.com...
>
> >> > On Nov 27, 3:49 pm, "Brian Selzer" <br..._at_selzer-software.com> wrote:
> >> >> "JOG" <j..._at_cs.nott.ac.uk> wrote in message
> >> >> Each individual that existed, exists, or can exist has a property that
> >> >> distinguishes it from all other individuals that existed, exist or can
> >> >> exist; so, yes, there is a property that the caterpillar and butterfly
> >> >> share.
>
> >> > Great, we have agreement :)
>
> >> >> The problem is: I don't think haecceity can be observed directly.
>
> >> > This time I agree with you (although I did have to look up what
> >> > 'haeccity' meant) - it is often the case that the identifier we need
> >> > isn't available to us (I mean we can't often check a butterflies dna
> >> > right...).
>
> >> > But we have to find a solution to this in the real world right - If I
> >> > have a butterfly, how do I know it came from the caterpillar from
> >> > earlier? Would you agree there are two options?
>
> >> > 1) Check an identifier that we can manage to observe (dna if we're
> >> > lucky, more likely the jar number we've kept it in, etc.)
> >> > 2) If we couldn't access that identifier (or it was just too much of a
> >> > pain to do so), we'd have needed to invent a new identifier as a
> >> > replacement, that was trackable (a representative identifer for the
> >> > insect's 'haeccity' - similar to what biologists do when they 'tag'
> >> > birds).
>
> >> > Again, all in the real world, before we get to a database.
>
> >> There is a third option: continuous observation. If you never take eyes
> >> (or
> >> the camera) off of the individual, there is no need to reidentify it, and
> >> therefore no need for a constant identifier.
>
> > How would you know that the insect your looking at now is the same one
> > as a second ago? You've tracked its (x,y,z) position. You've just been
> > continually checking another of its identifiers! And then you describe
> > the butterfly to someone else (after all this is shared data we're
> > talking about), and you refer to it as the butterfly you've been
> > watching, or the one on camera 2. More identifiers! 'Brian's'
> > butterfly or 'Camera 1' butterfly. In fact surrogates for the
> > butterfly's locational path!
>
> Yet the (x,y,z) position may have changed from a second ago. Clearly it is
> possible for all observable identifiers for an individual to change from one
> point in time to another. What is different in this case is that since it
> is being watched, both the old (x,y,z) and the new (x,y,z) positions are
> known, and the comparison can be made.

What do you think you are watching exactly? New and old (x,y,z) positions form a path, and that is what you are recording. I believe you are not correctly viewing the 'insect entity' as a thing that exists over a whole time period (t1 to t6 for example). The fact that I am currently at t3 is irrelevant. The path is still an attribute of the entity under consideration across its lifetime. The fact that I can't observe it (being temporally placed myself) is also irrelevant, because I just replace it by a surrogate (thats what surrogate means after all - "in place of"). I believe this is the same issue you had with workers who change their surname.

While we probably end up at the same conclusions of using a surrogate, I /think/ you are confusing the scope of the entity's you are considering. Say that t1 is the birth of the caterpillar, and t3 is when it becomes a butterfly. Then I am certainly not contradicting myself by saying:

butterfly entity != caterpillar entity
insect entity at t1 = insect entity at t3

similarly:
brian now != brian aged 5
person entity in 1970 = person entity in 2007

Its all relative identity. Regards, J.

>
> Spatiotemporal location can only be used to permanently identify individuals
> that have already come into existence. For those that haven't yet, it is
> not a rigid definite description and thus not a permanent identifier.
> Although this doesn't appear to apply in this case since if the butterfly
> exists, then the caterpillar must have already also existed, it is
> problematic from the standpoint of determining what is possible. For
> example, it is possible for there to be a new blue caterpillar at point
> (1,2,3) at noon today, and it is also possible for there to be a new red
> caterpillar at point (1,2,3) at noon today; but it is not possible for there
> to be both a new blue and a new red caterpillar at point (1,2,3) at noon
> today. So point (1,2,3) at noon today has multiple possible
> interpretations. It may seem like splitting hairs, but I think that there
> should be a different identifier for the possible blue and the possible red
> caterpillars since they are obviously different possible organisms. If
> point (1,2,3) at noon is used to identifiy both possibilities, then that
> could introduce ambiguity into the determination as to whether one of the
> two possibilities can become actual.
>
>
>
> >> >> If one were able to examine the history of the butterfly, one should
> >> >> be
> >> >> able
> >> >> to determine that it coincides with the history of the caterpillar--up
> >> >> to
> >> >> the point of the initial snapshot. The problem is: I don't think
> >> >> history
> >> >> can appear in a snapshot.
>
> >> > I get your gist here but hope we can come back to it after you've
> >> > looked at the above question. Regards, J.
Received on Fri Nov 30 2007 - 17:25:16 CET