[Top] [All Lists]

Re: [ontolog-forum] Two ontologies that are inconsistent but bothneeded

To: "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Chris Partridge" <mail@xxxxxxxxxxxxxxxxxx>
Date: Sat, 9 Jun 2007 10:32:48 +0100
Message-id: <002801c7aa79$25aba880$0200a8c0@POID7204>

Hi Bill,


Seem comment on point 4) below.


From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Bill Andersen
Sent: 09 June 2007 02:15
To: [ontolog-forum]
Cc: Pierre Grenon
Subject: Re: [ontolog-forum] Two ontologies that are inconsistent but bothneeded


Hi Pat...


Wow..  That was a lot of writing.  Forgive me if I fail to generate so long a discussion -- it is simply outside my ability.  A couple of comments, though.  And a pre-apology for top-posting, but it's simpler to say what I want as systemic comments on your post rather than a point-for-point response.


1) You called on Barry to consider adopting Quine's doctrine for existence.   To borrow your example from below:


          (ist Morning (that (inside Fritz Bratwurst)))


By this, you are asking the user of your ontology to accept propositions, as they do fall under the quantifiers in IKL.  While I don't have a problem with that (and in fact really like that feature of IKL), this is hardly a benign, pedestrian, work-a-day kind of entity to introduce into the kinds of engineering ontologies that people actually build, cf:


Ive never seen any convincing pragmatic or 

engineering argument for insisting on this as a 

rigid distinction


But while you find the continuant/occurrent distinction distasteful, you don't seem to mind propositions, the existence of which by the Quine doctrine you are definitely committing to.


2) If the continuant/occurrent distinction doesn't make any difference insofar as our use of terms to refer to temporal phenomena is concerned, then we run into another problem.  So you don't like that distinction.  How about presentism?  Your philosophy is very close to empiricist and verificationist, so I'm guessing (and I admit I could be wrong) you will lean toward presentism.  If you want to construe say, me, as a 4-dimensional object, then presumably you don't believe in the existence of any of my future or past time slices.  Would that be fair to say? 


3) As far as "convincing pragmatic or engineering argument" goes, would not such arguments be empirical and/or anecdotal by nature?  If so, then accept the work our ontologists at OW have done as such evidence.  We use every day a bi-categorial upper level of the kind exemplified by BFO, Cyc, and DOLCE, and have found it quite useful, both in teaching and in practice.  If you'd like to see some of these ontologies, we'd be glad to show them to you.


4) Again, following Quine's doctrine, what are these things for which the continuant/occurrent distinction is incoherent?  Presumably, you'd want to be quantifying over some class of objects for which you'd like to state some axioms governing, e.g., property change over time, however that comes out in your favorite formalism.  Then, by Quine's doctrine you're committing to the existence of those things.  Let's call them Continuoccurrents.  Now you have to elaborate your theory of Continuoccurrents and distinguish them from temperatures, numbers, properties, propositions and all the kinds of other things you have in your ontology.  Doesn't sound to me like that project is any less problematic than the defense of either bicategorialism, 4D, or any other metaphysical framework.  By this I mean on a practical, engineering level.


It seems, to me at least, there is a difference between the continuant/occurrent distinction and some of the other choices. These other choices (e.g. 4D) seem to be metaphysical, in that it is difficult to devise an empirical check on whether they are correct. With the continuant/occurrent distinction there seem to be cases that question whether it partitions objects. You know the standard philosophical cases – avalanches and waves – as these have been discussed before. In ontologies that deal with engineering artefact, the same phenomena seems to arise when (when we have a similar structure where) objects are the components for other objects built out. A simple example would be a network of systems, sometimes people see it as the systems networking, sometime people see it as a network that things happen to – e.g. it goes down for a while. To go back to Barry’s example, some biologists see human bodies, e.g. Fritz’s, as a process, with temporal parts – and would find it odd to have to distinguish between Fritz’s body and Fritz’s body’s life. It seems more as if the distinction is about different ways of looking at things, that sometimes can usefully be applied to the same thing.


My personal experience is that when dealing with the large bodies of data that exist in operational systems, when constructing simple taxonomies of the artefacts this data refers to, I am (reasonably) often faced with a problem about which category I want to put them in – and what category to put there more general supertypes that seem to include both occurrents and continuants. Of course, I can devise a practical workaround (for each of these problematic classes of objects, introduce two objects – the object and its life – and ignore feelings that these seem reminiscent of Ptolemy’s major epicycles) but this adds noise.


It also seems to me pragmatic to, when dealing with large systems, try to ‘cut nature at its joints’ and not have too many workarounds making the systems more complicated than they need to be. Hence my suspicions (and maybe Pat’s) of this distinction.


I should add that I think Barry’s paper is excellent – it is just that I cannot see in it a convincing practical case for continuants as a separate category of entities. Also, a minor point:


“The background motivation is, of course, the widespread tendency on the part of contemporary analytical philosophers to believe that they must maximalize ontological parsimony

at all costs. We, in contrast, are not concerned by a motivation of this sort. We are interested not just in the theoretical elegance of ontologies but also in their practical utility. We thus prefer to conceive debates about reduction and reconstruction as belonging to the domain of logical representation rather than to ontology properly conceived.”


 I think Barry exaggerates the position of contemporary analytical philosophers and parsimony. Parsimony has a practical dimension, particularly with regard to knowledge, as is evidenced by, among other things, its use in justifying scientific theories. (e.g. http://en.wikipedia.org/wiki/Parsimony  “In science, parsimony is preference for the least complex explanation for an observation. This is generally regarded as good when judging hypotheses. Occam's razor also states the "principle of parsimony".” - As this implies, parsimony limits the reduction of complexity with the requirement for an explanation.) Managing complexity is one of the major issues facing people dealing with large computer systems.





On Jun 8, 2007, at 17:39 , Pat Hayes wrote:

An example is described here:





Hey, nice survey. Utterly wrong in its 

conclusions, but nice :-). I'm happy to welcome 

you to this debate which many of us have been 

involved in for quite a long time. (see for 



But you come to the wrong conclusion. These two 

'irreconcilable' ontologies ARE reconcilable, if 

one does things right. The basic error is to 

assume that what a philosopher means by 'exists' 

has to be rendered into the logical existential 

quantifier. That is good form, perhaps good 

doctrine, when the game is to use formal logic to 

sharpen philosophical debate; but that is not (or 

at any rate should not be) what we are trying to 

do here. The only sensible engineering attitude 

to take towards the logical existential 

quantifier is that it means "is an entity which 

can be referred to", i.e. an entity which is the 

denotation of a logical term; which as long as we 

are using a reasonably classical logic is 

essentially vacuous, of course. In a pluralistic 

ontological framework, this cannot usually be 

interpreted as any philosopher's notion of 

existence. Those notions have to be treated as 

classes or properties. Yes, existence IS a 

predicate, when there are many notions of 

existence to be considered. It has to be in any 

logic which is intended to support 

interoperability. (See the regrettably brief 

discussion at 

. Sorry, I know that to say this to a philosopher 

is like farting in church.)


After thinking and arguing about endurance and 

perdurance for longer than I care to remember, I 

have come a rather mundane conclusion which can 

be summed up as follows: the continuant/occurrent 

distinction is basically a distinction between 

*how we use names* when talking about 

spatiotemporal entities. It should not be seen as 

a fundamental ontological distinction: it is 

merely a linguistic distinction between modes of 

_expression_. Things we call continuants are things 

for which we tend to use the same name at 

different times, so it is natural to encode 

changes to their properties by attaching the 

temporal parameter to their properties and 

relations rather than to them: we write things 



(inside Fritz Bratwurst Morning)


but we don't tend to talk of Fritz having 

temporal parts. Special terminologies are used to 

distinguish these temporally-sensitive relations 

and properties: "fluents", "roles".


Occurrents, on the other hand, are things that we 

do tend to speak of as having temporal parts or 

'episodes', so it is natural to formalize 

temporally-relative talk of those entities by 

attaching the temporal qualifier to the name 

itself. If Fritz and the Bratwurst were 

occurrents, we might write


(inside (episode Morning Fritz)(episode Morning Bratwurst))




If one puts all philosophical discussion aside 

for a moment and asks for a purely formal, 

syntactic, way of distinguishing these ways of 

describing things, what it seems to amount to is 

where to attach a temporal parameter to a 

time-free assertion. One might pose it as a 

challenge: given that


(inside Fritz Bratwurst)


is true during a time-interval




invent a systematic way of encoding that fact by 

incorporating the temporal parameter into the 

logical _expression_. There are basically three 

places it can go: attached to the entire 

_expression_ (the 'ist' version:


(ist Morning (that (inside Fritz Bratwurst)))


using the paraphernalia of context logic), or 

attached to the relation symbol (the first 

option) or attached to one or more of the 

argument terms (the second option). These 

correspond respectively to the 

hybrid/context-logical, continuant and occurrent 

ways of treating time.


So, can these co-exist? Yes, of course. One can 

use both (in fact, all three) modes of _expression_ 

in a single ontology, and in a reasonably 

expressive logic (like IKL) can even write axioms 

which relate them systematically. One does need 

to use some discipline, to keep things straight. 

One has to use even more discipline to use them 

both (or all) in ways that respect the 

philosophical prejudices of all users. For 

example, if someone insists, as you do, that it 

is incoherent or irrational to talk of temporal 

parts of a continuant, then one will probably 

need some kind of mechanical check to ensure that 

no entity is ever spoken of in both temporal 

styles. Such code could be written, but I 

personally see no practical use for it, and large 

amounts of harm caused by insisting upon the 

distinction it would be there to check.


The continuant/occurrent distinction seems to be 

of no actual value in real ontology 

engineering[1]: on the contrary, in fact, recent 

discussions on this very list and on 

public-semweb-lifesci@xxxxxx seem to illustrate 

what I have always found to be the case, that as 

soon as one gets away from nice homely examples 

like Fritz' bratwurst, the distinction becomes 

more and more tenuous, intuitions regarding it 

dissolve, and the insistence on its being a basic 

distinction rapidly becomes more trouble than it 

is worth, causing long and pointless debates and 

tending, if anything, to produce new, artificial 

barriers to interoperability rather than help 

with our practical goal. The real world is full 

of entities which are both 'continuant' and 

'occurrent', both thing and process: ocean waves, 

storms, weather fronts, the Olympic flame, a 

cumulus cloud, the interior of a Bessemer 

furnace, the Krebs cycle, a tomato ripening on a 

sunny windowsill, a cell expanding because the 

sodium pumps in its membrane are insufficient to 

oppose the osmotic pressure. The list goes on and 

on: and the Brentano/Chisholm doctrine of mutual 

incompatibility forces one to make all these 

pointless and harmful ontological distinctions 

between things and their lifespans, distinctions 

which arise solely from the artificiality of this 

doctrine of ontological apartheid.


Ive never seen any convincing pragmatic or 

engineering argument for insisting on this as a 

rigid distinction. There are plenty of purely 

philosophical arguments, but then there are also 

plenty of purely philosophical arguments in the 

other direction. As you know, there are almost no 

uncontroversial, universally accepted positions 

in philosophy. Academic philosophy has no "normal 

science", does not come to widely accepted 

conclusions, and does not progress by a kind of 

accumulation of evidence, where the task of each 

new theory or argument is to account for 

everything that earlier theories have done, but 

to do so better. Philosophy is an ongoing 

argument, where professional competence is 

demonstrated by the ability to find a new flaw in 

someone else's argument (which itself might be 

the finding of a flaw in someone else's argument, 

and so on for many layers). This means that while 

almost any nontrivial philosophical position can 

be bolstered by a long list of impressive 

references, it can also can be attacked by an 

equally long list of authorities who have argued 

the opposite. This is why I have often said that 

while philosophy can be of use to ontological 

engineering, the appropriate attitude to take 

towards a philosopher should be rather like one 

adopts to a pet dog: they need to be housebroken, 

properly trained and fed well, but it is most 

important not to let them feel that they have the 

upper hand. (I personally find the 

'intuition-pump' (in Dennett's phrase) that your 

paper obliquely uses, which I tend to attribute 

to Simon's definition of "continuant" as 

something which, when present, is wholly present, 

quite unpersuasive because it is circular. If I 

have temporal parts, then I am NOT wholly present 

now. So am I wholly present now? In a sense yes, 

in another sense no. I can run my intuition 

either way.)


One pragmatic argument I have heard is that the 

distinction provides a kind of conceptual 

scaffolding, an ontological discipline which 

helps users render their intuitions more clearly 

by requiring them to think more clearly, 

basically. While this general idea certainly has 

some merit (as for example in the successful 

"Ontoclean" notions) it seems to have no real 

purchase when applied to the continuant/occurrent 

distinction, since the only purpose of making 

this distinction is to maintain the distinction 

itself. If one simply denies it then nothing is 

thereby lost: the only result is that 

distinctions, equally artificial, which have been 

produced by this splitting (such as the required 

distinction between Fritz and Fritz's lifespan) 

are themselves no longer needed. The resulting 

wave of simplification and unification rolls 

through the ontology like a kind of global 

relaxation into a simpler, and yet ironically 

more expressive, ontological framework. So the 

'discipline' which this framework requires serves 

only to maintain the framework itself: it is like 

a parade-ground exercise of marching in step.


I don't mean to argue that the intuitive 

categories of 'enduring thing' and 'event' are 

vacuous or useless. To the extent that they fit 

with ontological intuitions, and with linguistic 

usage, they are useful and important. But one can 

admit all that, and even include them as 

categories in a formal framework, without 

requiring that they constitute a rigid taxonomy, 

so that every physical thing MUST be in exactly 

one of the two categories and as a matter of 

logical necessity CANNOT be in both. Things can 

be in both, and there is no need to be concerned 

about this or try to forbid it. One can be 

noncommittal about the category. Sometimes it is 

useful to speak of temporal parts of 

continuant-like entities. I had red hair as a 

child. Why should one not be able to render that 

by speaking of the child-temporal-part of me, and 

attributing the color 'red' to its hair? If that 

treats me as a process, I am perfectly happy to 

be regarded as a process when that is useful. For 

some purposes, indeed, it is difficult to see me 

any other way than as a process (as for example 

when we learnt that I lose and gain cells at what 

might otherwise be an alarming rate.) The logical 

sky does not fall when a temporal parameter is 

attached to a continuant-like name. It is 

perfectly clear what it means, even to those who 

feel that it ought to be meaningless. One can (in 

CL) even state conditions which translate this 

form of logical description to the more 

continuant-like form:


(forall (r (x Continuant)(t TemporalInterval))(if (r (x t)) (r x t) ))


Perfectly consistent, with a clear meaning, and it works.


(BTW, I suspect that nothing in the case which 

started this thread comes anywhere close to this 

degree of complexity or intensity of 

philosophical debate.)




[1] PS. I know that your framework and Dolce both 

use it, and are both used by real people in real 

settings. But that in itself is not evidence that 

a similar but simpler framework which does not 

have this distinction in it might not be even 

more use.


PPS. Although I am doing all this emailing on 

borrowed time, this issue is important enough 

that I will make the following challenge. If 

anyone has two actual ontologies (of a reasonable 

size, in a reasonable formalism) which satisfy 

Waclaw's **criterion** below for the reasons 

outlined by Barry and Pierre, then please send 

them to me and I will undertake to produce a 

single ontology, written in CL or at worst IKL, 

which is consistent but into which they can both 

be translated so as to preserve entailments. That 

is, my ontology may (will :-) require one or both 

of them to be rendered into a different form, but 

that re-rendering will not break any inferences, 

if used uniformly. I may need a week or two.



At 08:34 AM 6/8/2007, Waclaw Kusnierczyk wrote:

The discussion would certainly be made clearer if one could support the

claims with a simple example;  e.g., **two ontologies that taken together

are inconsistent, which cannot be reduced to a single consistent

ontology, and which both are necessary to cover the needs for all

involved in modeling the domain.**


As in mathematics, illustrative examples help in understanding dry

theories.  I sympathize with Bill, and would like to see a

counterexample to what he says.




Bill Andersen wrote:

Hi John...


On Jun 8, 2007, at 01:42 , John F. Sowa wrote:


Those are two important points, but they don't exhaust all the

options.  There are many cases where the ontologies happen to have

some features that create inconsistencies, but with some revisions

those inconsistencies could be eliminated by redefining some of

the terms.  There are also many cases where the same thing is

viewed at different levels of granularity or from different

perspectives.  Any inconsistencies caused by such methods

could also be eliminated, in principle.


However, the job of eliminating every one of the inconsistencies

that could arise could take an enormous amount of effort.  Instead

of striving for a global consistency of everything, it might be

better to adopt methods that don't require global consistency.


What I was more trying to get at was the notion of identity (or

perhaps unity) for "ontologies".  In Sean's original note, he said

something like "a single ontology cannot be used".  You just gave us

a recipe for how to make (IMO) a single ontology from Sean's

"inconsistent" pieces, via the use of reformulation of his pieces to

make them consistent, or via use of some kind of paraconsistency.


That was what I was trying to get to in my original note ­ loose talk

of "one single ontology for X can't ..." is usually based on equally

loose understanding of the terms "ontology" and "can't".   Sorry I

wasn't more explicit about this in my original note.








Wacek Kusnierczyk



Department of Information and Computer Science (IDI)

Norwegian University of Science and Technology (NTNU)

Sem Saelandsv. 7-9

7027 Trondheim



tel.   0047 73591875

fax    0047 73594466














IHMC                        (850)434 8903 or (650)494 3973   home

40 South Alcaniz St.   (850)202 4416   office

Pensacola                               (850)202 4440   fax

FL 32502                               (850)291 0667    cell

phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes




Community Wiki: http://ontolog.cim3.net/wiki/ 



Bill Andersen (andersen@xxxxxxxxxxxxxxxxx)

Chief Scientist

Ontology Works, Inc. (www.ontologyworks.com)

3600 O'Donnell Street, Suite 600

Baltimore, MD 21224

Office: 410-675-1201

Cell: 443-858-6444


No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.472 / Virus Database: 269.8.13/840 - Release Date: 08/06/2007 15:15

No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.472 / Virus Database: 269.8.13/840 - Release Date: 08/06/2007 15:15

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (01)

<Prev in Thread] Current Thread [Next in Thread>