On Aug 11, 2009, at 3:07 PM, Chris Partridge wrote: (01)
>>
>> Can you repeat that example? I seem to have missed it.
>
> Ingvar,
>
> Take two spatiotemporal points in a four-dimensional
>> manifold,
>> ascribe to both exactly the same mass density, then you have (on my
>> view)
>> two 4D-points, one property, and two property insstances.
>
> For some 4D extensionalists, you only have two 4D-points (also called
> property instances) and one property.
> So we have two different (mainstream) views to reconcile.
>
>>
>> Ingvar J (02)
Ah, I see. Sorry, I did not think of this being an example, no doubt
because of my common-sensical bias :-) I really have very little
intuition about how best to describe a 4-d manifold. But doing my best
(and thinking of a swirling mist), I really do not know how to
distinguish the two cases here. We are talking of spatiotemporal
points, and mass density at those points. If the density is conceived
of as a property of points, then there is one property which holds of
two entities, called points. One might formally write this,
caricaturing somewhat, as
(DensityInQuestion point1) & (DensityInQuestion point2)
Now, how many property *instances* are there, is a question which I do
not know how to answer, nor do I care what the answer is, since it
seems to have no bearing on how the situation will be described in the
formal notation being used. So why are we even discussing this
question? One thing I am absolutely sure of is, I do not want to have
to write things like
(exists (x)(and (InstanceOfProperty x DensityInQuestion) (LocatedAt x
point1) ))
in order to formalize some purely philosophical intuition, or to be
able to distinguish two rival such intuitions. If some category of
entities can be eliminated without expressive harm, the best solution
is to end all debate about their true nature by eliminating them, or
even better, by not introducing them in the first place. (03)
>
>>
>>> I am not aware of any definitive proof that property instances, 3D/
>>> 4D and
>>> extensionalism are either independent or dependent. It does seem as
>>> though
>>> 4d + extensionalism (for which Matthew sometimes uses the shorthand
>>> '4d')
>>> does have implications for property instances. However, these things
>>> are so
>>> entangled that there is always wriggle room. I interpreted your and
>>> John's
>>> comment that you had some way of showing that they were independent
>>> simpliciter. So, to be clear I have no way of showing these are
>>> orthogonal
>>> or not and would be interested in any such proof as my experience is
>>> that
>>> these matters are entangled - so some such proof would be useful.
>>
>> I will try to sketch the argument, though I would hesitate to call it
>> a proof. It amounts to defining a syntactic transformation from one
>> ontological formalism style to another, and then observing that one
>> of
>> these can reasonably be seen as a formalism of the 4D picture, and
>> the
>> other of the 3D one. The basic point is that there are only two ways
>> to insert a time parameter into a 'static' description: it either
>> gets
>> attached to a relation name as an argument, or to an individual name,
>> converting them to a term. One writes either (R a b t) or (R (a t)(b
>> t)). The first is naturally read as a continuant-style description,
>> using time-dependent fluents to talk of things whose identity is
>> considered to be timeless, the latter as a 4D one, in which
>> assertions
>> are made timelessly about 'slices' of a 4D entity. (There are other
>> ways, but they all involve changing the logic in some way, eg by
>> adding temporal contexts or tenses.) Basically, and oversimplifying
>> things greatly, one can convert from 3D to 4D and back by 'moving'
>> the
>> temporal parameter between these two positions. This is an
>> observation
>> about the formal notation, of course, but the philosophy is basically
>> irrelevant until it gets cashed out in a formal expression of some
>> kind. Whatever your views are on property instances, in particular,
>> can (if they are relevant to the final ontology) be ultimately
>> expressed in one of these ways, and when it is so expressed, can be
>> almost mechanically transliterated into the other, and from there
>> 'read back' as being about the other kind of temporal entities. I
>> realize that this hardly constitutes a philosophically valid form of
>> argumentation, but then of course we are not here doing philosophy,
>> but rather ontology engineering: right?
>>
>
> Can I make an number of points.
> Firstly, can I say that I think Matthew's original comment was not
> about
> whether one can do this translation or not - and I am not sure how
> having
> the translation in itself proves (or disproves) independence (04)
I agree, it does not amount to a proof. (05)
> - though the
> details may be illuminating. I think my comments below will help to
> make
> this point clear.
> Secondly, I cannot see what practical relevance whether one has this
> translation makes to the current enterprise. So I am puzzled why
> people are
> making such a big deal of it.
>
> Let me quickly state my position wrt the translation. I believe that
> there
> are significant problems in formalising the position with sufficient
> accuracy to make it useful. While one may be able to easily
> translate 80% or
> 88% or 99%, this is not good enough. I suspect that when/if this has
> been
> done, there will be awkward problems with the translation, which
> will become
> significant when one deals at the industrial level. (06)
Possibly, but it would be an interesting challenge, and one that might
reap considerable benefits if it were pursued. But not in this forum,
to be sure. (07)
> So if one were to offer
> a 3d/4d translation service, one would be expected that it would
> work with
> an accuracy at the (say) five of six nines level on huge quantities
> of data.
> My gut feel is that people would sensibly much rather rely on rule
> of thumb
> and experience than theoretical rules. (08)
Maybe we work with different kinds of people :-) (09)
> My gut feel is that why it has not
> yet been done. But I have no proof at all of this intuition.
>
> I can see the outline of your argument, but for me the flaw is "the
> philosophy is basically irrelevant until it gets cashed out in a
> formal
> expression of some kind." I would agree that once one has grasped
> what needs
> to be formalised, then one can work with the formalisation - the
> problem is
> getting to the grasping. (010)
I do however think a great deal of time and energy is spend sorting
out agreements on issues which do not in fact matter to the final
formalism at all. Counting property instances is one good example,
above. (011)
>
> It also seems to me to miss the key problem - and this may be at the
> heart
> of our disagreements - and it may arise because we deal with different
> problems in our work.
> Let us assume that (a) we have formalised the 3d and 4d view and (b)
> we have
> a formal translation between the two (so these can be discounted as
> issues).
>
> We approach a domain and we find there are a number of communities and
> sub-communities and so already number of different sets of terms. We
> start
> by translating the different sets into formalisms.
> We soon realise a number of things.
> 1) That the different sets capture well different aspect of the
> world (the
> ones that were uppermost in the minds of people using them) - and
> other
> aspects less well.
> 2) That due to historical and other factors, these sets are internally
> heterogeneous with respect to various principles including 3d/4d,
> identity,
> etc. - and this is one reason what there are sets of different terms.
> 3) That in many cases it is not completely clear what the terms
> refer to -
> and that the experts are not able to easily resolve the issues in a
> way that
> enables them to be harmonised.
>
> So, let's say we decide we would like to arrive at a formalism of
> these sets
> - to agree on a basic set of terms. And we consider two options
> Option (a) We take all the terms as they stand
> Option (b) we agree on some common framework within which we
> regiment the
> different terms
>
> It is my experience (b) is a much better option, particularly if you
> are
> working in a team. People have a framework to work within.
> It is also my experience that the 3d/4d choice is one of the useful
> elements
> of the common framework - and that it is more important to make the
> choice,
> than which choice is made.
>
> So it seems to me you are seriously discounting the effort it takes to
> formalise things in such a way that they can be used at an
> industrial level
> - and focusing on what happens when that task is done. Perhaps, this
> reflects our different concerns. I just think it is very difficult
> when one
> deals with large industrial domains, to have a sharp enough
> understanding to
> produce a formalism that is useful, that is an improvement on the ad
> hoc
> situation that exists. And if one does not, the attempt at formalism
> seems
> like a theoretical nicety with no real practical benefits.
> What the common framework does is to increase the odds of success. (012)
I respect what you are saying and your experience which supports it. I
am coming from a different tradition where there is no single
'project' and no single 'community', and detailed such negotiations
are impractical, so one has to face up to the inevitablity of there
being alternative perspectives all in use, and the consequent need to
map between them (or deftly avoid them) as far as possible. (013)
<snip> (014)
>>>
>>> .... As has been pointed out a number
>>> of times,
>>> 3d/4d is shorthand for positions on the reality of change.
>>
>> Um... that is not how I am understanding it. The *reality* of change
>> seems to me to be beyond rational dispute. I see the distinction as
>> being about how best to formally describe change.
>
> I think we have discussed this before.
> There are lots of reference to the unreality of change, series A and
> B, etc.
> which I raised before - so I will try a different tack.
>
> Consider a situation where PatH is in his office at time t1, and in
> the
> garden at time t2.
> We can all agree that, in one sense, there has been a change (015)
Exactly. And that is what I mean by 'change', the pre-theoretical
notion. (016)
> , but ....
>
> A 4d-ist (or whatever) says that the time-slice of PatH at t1 is
> inside his
> (4d) office - and the time-slice of PatH at t2 is inside his (4d)
> garden. (017)
Using 'is' timelessly, of course, and hence potentially misleadingly :-) (018)
> Ok, there is no object here that is changing, the same object that is
> different in some respect - and no object that is a change. We have
> what
> Russell called an at-at description of change (at-t1-at-t2). (019)
Exactly; the *description* is different. But that there has been (what
is in normal English called) a change in the part of the world being
described here, is surely not open to doubt. And there *is* a "same
object which is different". When you refer to PatH-at-t1, you are
mentioning PatH. That is the same PatH that is being referred to in
the construction PatH-at-t2. These things that have the timeslices are
*very* similar to what the other folk call continuants. In fact, you
can treat all of the DOLCE/OBO framework as being about 4D things, if
you simply remove the insistence made in those ontologies that
continuants and occurrents be mutually exclusive. A 4D PatH is both a
continuant and an occurrent; both the continuing thing and his
lifehistory; a possibility which is of course explicitly denied by the
OBO foundational philosophy, unfortunately. (020)
>
> A 3d-ist (or whatever) says at time t3, that at t1 PatH was inside his
> office - and at t2 PatH was inside his garden (021)
The use of tensed verbs suggests a presentist description, which I
wasn't even considering as a viable alternative for ontology work. We
don't want ontologies which become obsolete just due to time passing. (022)
> - and that between t1 and t2
> PatH's position changed. Change consists of (exactly) the same
> object being
> different at different times. (023)
The same (continuant?) object having different properties at different
times, in the 3.1D (see below) perspective, yes exactly. (024)
> And one can talk of this change. And these
> changes are re-ified as occurents.
>
> Now what it seems to me you do is to give a 4d interpretation of the
> 3d view
> - typically based upon time-slices. Nothing wrong with that (I think
> it is
> in many ways sensible), unless you deny there is such a thing as the
> 3d view
> that the 3d-ist (presentist) holds. (025)
Of course I do not deny that. I was assuming a distinction between 3-D-
ism and presentism, which you apparently conflate, but that is just a
matter of terminology. I'm happy to use yours, if you can come up with
a name for the DOLCE/OBO perspective, which I have been calling 3D.
Perhaps 3.1D (by analogy to 5.1 sound systems, which makes time into
the subwoofer channel, which has a certain appeal.) (026)
>>
>>> For an
>>> extensionalist the matter is solved. What is odd (for me) about your
>>> position is that you do not seem to see any need to a criteria of
>>> identity,
>>> while arbitrary applying your own intuitive judgements on this.
>>
>> I do not think it is useful to engage here in a philosophical debate
>> about the merits or otherwise of identity criteria. One thing is
>> clear, that different people and communities will use many different
>> such criteria for many different, but to them compelling, reasons.
>
> My experience is that they do not have an systematic criteria. That
> is a
> common problem I face. (027)
Well, if they manage to get along, maybe they don't *need* systematic
criteria. (028)
>
> It
>> is therefore not appropriate or useful to set out to impose any one
>> such discipline on the entire world of ontology users, no matter how
>> convincing one may feel that one's philosophical credentials are.
>
> Agreed, and I do not believe I have done that. And I am not sure where
> philosophical credentials come in. (029)
Sorry, credentials was the wrong term, and has a regrettable ad
hominem sense that was unintended. I meant, no matter how sure one is
of the philosophical foundations of the discipline. (Because the other
positions have their own, different but equally secure such
foundations.) (030)
> Similar points apply to the use of notation, logic, etc.
>
> IMO,
>> the responsible ontology engineering position should be to make these
>> explicit and try to find accurate ways to map between them or make
>> them at least mutually comprehensible, but not to make judgements
>> about their correctness or otherwise, since those decisions are
>> determined by criteria which lie outside the purview of ontology
>> engineering,
>
> I am not sure you can say a priori that just because a criteria is
> studied
> in philosophy it is not relevant to ontological engineering. (031)
No, I wouldn't go that far. My point is only that the criteria that
govern such decisions may be based on pragmatic or social or
historical conventions that resist philosophical analysis and in case
are not open for debate. Some of the more outree kinds of measure
used in, for example, medicine seem to have this character. They are (032)
> While academics
> may wish to regard their departmental divides as insurmountable, the
> world
> is not divided in the same way. How can one exclude the possibility
> that,
> for the purposes of ontological engineering, some criteria studied
> in the
> philosophy department may (or may not) be useful? (033)
Indeed. But my own experience in this regard has not been very, shall
we say, encouraging. Most of the issues studied in philosophy
departments seem to have very little bearing on anything of interest
to anyone outside philosophy departments, in my experience. (034)
> (BTW in the history of
> information technology, one theme is that as various technologies have
> developed the notion of identity has refined - so there is some
> historical
> evidence that tightening up the notion of identity was linked to
> advances in
> information technology). (035)
Hmm. So, what do you think has happened to notions of identity between
documents since the advent of CSS style markup in HTML? Or when texts
can 'contain' movie fragments or constantly updated news feeds? Or
even to notions of identity between such things as numbers, in XML
Schema datatyping (with its notions of 'facet')? Or between web
'resources' which can change every time they are accessed, like an RSS
stream, yet are treated as having an identity by virtue of the HTTP
protocols which locate them? Or of data structures which have internal
dynamic states? Seems to me that philosophical analysis is struggling
to catch up with the realities of IT innovation in these, and many
other, areas. (036)
>
> such as in the history of a science or the practice of a
>> community. Hence my deliberate avoidance of this topic in these email
>> threads. What I think we can usefully do, perhaps, is to help people
>> state their identity criteria more clearly and explicitly; but even
>> there, my experience has been that they often have quite a clear
>> idea,
>> and the apparent confusion arises from it not fitting into some
>> philosophical category.
>
> Interesting, my experience is that even before one starts digging,
> fault
> lines appear in the identity criteria. I suppose you would regard any
> attempt to analyse the identity criteria as pointless, but my
> experience is
> that where any criteria exists it is extremely heterogeneous. (037)
I agree, but I do find this necessarily a source of regret, or feel
that the situation calls for correctional action. (038)
> But I suppose
> we just have to note our differing experience.
>
> As I hoped I made plain above, my desire here is not to impose any
> particular view on a global basis. (039)
When thinking, as I do, about the semantic web, the 'project' is
global. No doubt this helps explain our differences of emphasis. (040)
Pat (041)
> But to suggest that it makes sense to
> agree what view one is using in a particular project and stick to
> it, and if
> a one view has practical advantages over another to take account of
> this.
> Much as one might agree to use Java to code a particular system, or
> intuitionistic logic to formalise something. Or, as John keeps
> suggesting CL
> for this ontology.
>
>>
>> Pat
>>
>
> Chris
>
>
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