Dear Pat, I wish it were this simple: I had thought that Pat Hayes had definitively demonstrate years ago that 3D and 4D are just syntactically different ways to say the same thing about entities in time, and any assertion in one modality can be translated into an assertion with the same meaning in the other. [MW>] What Pat has shown is that the two approaches can interoperate and even be expressed in the same syntax. Thus it is likely that the two approaches are approximately equivalent, and so the argument should move on from a right/wrong discourse to a lets understand why they are different (but so what if they are). The only thing that I have seen that creates an incompatibility is an assertion in either view that entities in the other frame **do not exist**. [MW>] Let’s be clear it is an inconsistency in the ontological commitments, rather than an incompatibility in the interoperability sense that is the issue. This is not merely an assertion, it is a logical consequence of the different ontological commitments they make. Such an assertion is, as Pat suggests, a religious dogma, quite useless in practical work, but for those who want to assert an incompatibility of the two viewpoints, it serves to create one. [MW>] It just means you need to understand the choices you have made and their consequences. Let me give one example of a consequence. People who choose a 4D approach generally commit to an identity basis for particulars that if two objects are coincident then they are the same thing. So let’s take a particular example of Barack Obama, and President of the United States. Are they the same thing or not? Well they are coincident now, so they are the same thing now, but is that enough to say they are the same thing? What about when George W Bush was president? In 4D this is easy. The whole life of Barack Obama is not coincident with the whole life of The President of the United States, so they are not the same thing. But The President of the United States does consist of the various incumbents, just whilst they were incumbents. It is hard to get to this whilst also insisting that things are wholly present at each point in time. If you aren’t insisting that, and you are saying that you want to talk about states of things, then you have abandoned the 3D position and adopted some version of 4D. One or the other view (3D or 4D) may be convenient for different tasks, and I think ontologists should feel free to use either, knowing that an accurate translation is available when needed, as PatH has said. [MW>] Yes indeed. I don’t think that is the issue. The issue is whether you can ignore the difference, or whether you need to be aware of which choice you have made and its consequences for what you are doing. Regards Matthew West http://www.matthew-west.org.uk +44 750 338 5279 PatC Edward Barkmeyer <ebarkmeyer@xxxxxxxxxxxx> , 3/17/2015 12:58 PM: At the risk of putting my oar into already treacherous waters… :-) As a practicing knowledge engineer, I build ontologies to solve some identified problems. There are situations in which the Quine approach (static worlds) is adequate, and others in which the 3D approach is most convenient, and still others (more rare) in which the 4D approach is necessary. Like John, I don’t find apostolic promulgation of any of those philosophies to be useful. (It is a fine philosopher’s thing, but that is not my concern.) I can agree with Pat that CLIF allows me to express any of these approaches conveniently, but I disagree that the distinction is just a ‘difference in the choice of syntax’. The underlying theory/philosophy definitely enters into the choice and use of the syntax. The elements of the universe of discourse have ‘problem-specific meaning’; they are not just mathematical objects. (I think Matthew said that.)
I absolutely agree with your last sentence here, but I (now) draw a different conclusion from it. The universe of discourse is the world we are talking about in our axiomatized theories (=ontologies). And the things in this world are not just mathematical objects, but have meaning. (I would prefer to say 'are meanings', but lets us not quibble.) Exactly. But surely, a picture of all this in which the world being described is populated with things that last through time, and which MAY be talked about as continuants (if one is so philosophically inclined) and also MAY be talked about as 4-d entities extended in time (if ditto), but ARE simply what they are, which is things that can be talked about in several ways; surely, this is preferable to the two talkers being forced to talk about two distinct worlds populated by different things which, like matter and anti-matter, mutually annihilate if placed to close to one another. More prosaically, consider the situation in which a (single) world is described in these two different ways, and one philosophical camp's ontology supports a useful conclusion about that world, and it would be useful and public spirited to be able to re-cast this conclusion in the terms used by those on the other camp, so that they can make use of it rather than re-derive it in their inference engine. Right now this is a difficult exercise in ontology translation, but it ought to be so simple as to be transparent: after all, it is one single world they are both talking about, right? Finally, let me point out that (as I am sure you know) this particular issue has probably generated more philosophically motivated but ultimately useless prose and heat than any other issue in ontology engineering, and we are no closer to resolving the issues than we were thirty years ago. Perhaps reducing it to a relatively trivial matter of axiomatic style, and purging it of philosophical content altogether, might be a positive step. Of course, I do not expect any professional philosopher to agree, but then philosophers in our field are like dogs: excellent companions and often having remarkable talents, but dangerous if allowed to run loose and form packs, and needing constant training in obedience. Another of my pet peeves is the insistence of certain persons that any reference to future states requires some kind of modality, or ‘branching time’. There are situations in which you want to examine possibilia, yes. But for much knowledge engineering, I prefer the view that there is a world you take to be ‘actual’ and if there is time in that world, then there is, and some of that time can be in the future. -Ed From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of rrovetto@xxxxxxxxxxx
Sent: Sunday, March 15, 2015 8:56 PM
To: [ontolog-forum]
Subject: [ontolog-forum] Endurantism and Perdurantism - Re: Some Comments on Descriptive vs. Prescriptive Ontologies
You wrote: [MW>] The problem with combining endurantism with a process (or purdurantist) approach is that endurantism insists that physical objects wholly exist at each point in time and pass through time, which means that in particular that they do not have temporal parts. On the other hand a process/purdurantist ontology has physical objects extended in time (like processes) and hence they have temporal parts. Overcoming that contradiction is non-trivial without actually changing sides, and the choice between them is one of the core commitments one has to make.
You've described traditional views of perdurantism, and also what is often presented as a contradiction. The idea is to develop other more accurate conceptions of perdurantism/endurantism or some amalgam of the two seemingly opposing views. I doubt there is reason to make the distinction dogma, and from my experience it seems it's been accepted as such.
Now, in philosophy, some have questioned the wholly-present aspect, leading to a view according to which processes are persisting, wholly-present yet ongoing or unfolding (in no temporally-extended sense) entities (See Rowland Stout). In the applied side, as Galton et al. (Waterfall paper) have said "objects are points of stability" in virtue of processes they or their parts participate in. In my view, these are some steps to a more accurate ontological description of existents.
I believe traditional endurantism and perdurantism are too rigid and narrow in themselves, each picking out aspects of the world, but are at least two sides to the same coin in describing existents. If some are interested in collaborating on a paper--ideally funded as it is important in my circumstances--on these topics, contact me privately. As I said, I have one, but the area needs more work.
FYI: I've added 'Endurantism and Perdurantism' to the subject-line of this thread, and including the comment by Rich below (because I seem to be getting separate emails). For those responding further, I encourage responding with that addition in the subject for reference and consistency with the topic. It seems to me that combining the two - object properties and process properties - would be more realistic than separating them. It has been common practice to separate them for so long we should at least review the reasons why we don't, in practice, put them together. In games, the objects go through state changes and also appear to perform actions. Those would certainly be natural examples we could discuss it that way. Starships, Klingons, Martians, ray weapons, shields, sick bay, Captain Kirk, Scotty, the whole cast, the Conn, and all those objects could be used as examples. But isn't the idea to construct "Scriptive" ontologies, i.e., task schedules, as stored or calculated, for each object? One purpose of the historic separation was for partitioning the program, from the data tables, so that the software could be generalized for use in wider application domains. But that separation changes the design to ensure that an API for the scheduler would be distinct from an API to the script tables manager - SQL or NoSQL. Separating the two subsystems over the years has gradually made each subsystem more general, more efficient at its subtask, and more complete in its treatment of the combined System, both software and tables. HTML is an example of scripted layout, and there is an ontology of objects and operations that can be extracted from the various verbs and nouns in HTML pages. HTML also separates out the verb parts from the declarative parts, and the latest version is syntactically closed, so it's hierarchical and very easy to parse. Yet it still maintains the separation of objects from processes. Why is that the choice made instead of putting them together? What would be gained or lost by integrating them? Sincerely, Rich Cooper, Rich Cooper, On Sun, Mar 15, 2015 at 1:28 PM, Matthew West <dr.matthew.west@xxxxxxxxx> wrote: Dear Robert, There is actually a problem here. Just a quick note on a passage in this helpful thread (not intended to deviate from the topic at hand, but important all the same)...
MW: "The problem I have with this insistence that activities/processes/events are disjoint from physical objects is that it requires two objects for (amongst other things) me, one for me as the physical object, and another for the activity of my life. I’m with John S. (and some others) who take a process approach, seeing physical objects as (relatively) slowly changing processes." I agree with not being entirely fond of the traditional object-process distinction as such. To me it does not seem to capture the fluid (so to speak), processual-yet-persisting aspect of the world. However, one does not necessarily have to chose either the process-ontology approach or endurantism. One can think outside of the box and combine qualities of each. The task would then be to solve whatever philosophical (or other) problems that arise in doing so. This has been attempted, at least in philosophy. In fact describing physical objects as slowly changing process is moving toward that attempt. Anyway, one need not feel confined to the traditional distinction as if there were no alternatives. One certainly not feel as if we could not create (or discover) alternatives! [MW>] The problem with combining endurantism with a process (or purdurantist) approach is that endurantism insists that physical objects wholly exist at each point in time and pass through time, which means that in particular that they do not have temporal parts. On the other hand a process/purdurantist ontology has physical objects extended in time (like processes) and hence they have temporal parts. Overcoming that contradiction is non-trivial without actually changing sides, and the choice between them is one of the core commitments one has to make. On Sun, Mar 15, 2015 at 10:17 AM, Matthew West <dr.matthew.west@xxxxxxxxx> wrote: Dear Thomas, To: Ontolog Discussion Group From: Tom Johnston (new member) [MW>] Welcome! I would like to comment on the current discussion about SMEs and ontologies. (note: in the upper-level ontology I developed in my recent book “Bitemporal Data: Theory and Practice” (Morgan-Kaufmann, 2014), objects and events divide the world between them; they are exhaustive of what there is, and nothing is both an object and an event. Objects come into existence, cease to exist and, while they exist, change from one state to a successive state by participating in events. I consider this the formalization of an upper-level folk ontology which is the ontology common to all relational databases. [MW>] That is not true, relational technology is neutral in ontological commitments, except that it requires that tables cannot themselves be instances of other tables. However, I accept many relational databases adopt this commitment. The problem I have with this insistence that activities/processes/events are disjoint from physical objects is that it requires two objects for (amongst other things) me, one for me as the physical object, and another for the activity of my life. I’m with John S. (and some others) who take a process approach, seeing physical objects as (relatively) slowly changing processes. During the JAD sessions (see below), the initial statement of requirements will be transformed into a different set of requirements that are not simply the initial requirements stated in greater detail. The initial set of objects, events and transformations will be similarly transformed as the BA helps the SMEs realize (a) ambiguities inherent in their original statement, (b) generalizations of their requirements that will do what they require but also additional useful things; (c) restrictions on their requirements because the current state of technology at the enterprise would make their satisfaction unacceptably expensive; and (d) a sorting of initial requirements into do-now and do-later categories, based on dependencies among the requirements, and on the need to keep the project on-time and under budget (so both the BA and the SMEs, whose names are most directly attached to the project, will look good to their bosses when the whole thing eventually moves into production status). [MW>] The challenge I find is in validating the requirements (providing evidence to support them). JAD: joint application development (a somewhat outdated term). [MW>] I think SCRUM is the current incarnation of this. It is this: SMEs generally do not know what they are talking about. To repeat: SMEs generally do not know what they are talking about. [MW>] John made a similar point, and I agree. I was too polite in my earlier post. In particular they generally don’t know what they don’t know. For anyone familiar with Plato's Socratic dialogues (early and middle period dialogues), I can make my point like this: SMEs (Gorgias, Meno, Protagoras, etc.) are the protagonists of Socrates (the BA) in those dialogues. Those SMEs are the ones who profess to know something – about knowledge, justice, courage, etc. Socrates engages each of them in a dialog which always ends with Socrates demonstrating, usually by eliciting a contradiction from his protagonist, that the SME actually doesn't know what he claims to know. But there is one difference between Socrates and today's BAs. Socrates is content (pleased, in fact, his protestations to the contrary) to show that his protagonists don't know what they claim to know. Today's BAs, however, cannot afford that luxury. Today's BAs must somehow guide her SMEs from ignorance to knowledge, from vague, ambiguous, incomplete or otherwise inchoate initial statements of what they want to a final statement which will mediate between them and the developers who will implement their requirements. One conclusion from all this is that the (ontologically-adept) BA must take a very active role in eliciting and clarifying definitions of the objects and events of concern to the enterprise. Her role must not be tidying up around the edges of what the SMEs initial come up with as a requirements statement. She must not use a light touch. She must challenge her SMEs as aggressively as Socrates challenged the self-proclaimed experts he engaged with. [MW>] I agree. Is there any additional guidance I can suggest, other than these very general comments? There is. I would like to suggest that before we begin eliciting ontological commitments from SMEs, we should clarify (a) what we are defining, and (b) what a definition is. (3) What are we defining when we ask SMEs for definitions? Let's take Customer as an example. In any enterprise, in any JAD session, with any group of SMEs, when we ask “What is a customer?” (the same “What is X?” question form as Aristotle's most basic ontological question, ti esti?), surely we must be asking for something besides a dictionary definition. We don't need SMEs to formulate general definitions, whether they are do-it-yourself dictionary definitions, or definitions defining nodes in a taxonomy whose linearly parent nodes, up to the root node, have already been defined. We are asking our SMEs what a customer of our enterprise is, that is, what a customer of our enterprise in fact is, not what the SMEs think a customer of our enterprise ideally should be. [MW>] Yes. When I was talking about an evidence based approach in my response to John, this is the kind of thing I was meaning. In any relationship of a set and its immediate superset, the immediate superset defines a universe of discourse from which the members of the set are chosen by means of that rule. For example, the set Customer will have (whether represented as such in a database or not) as an immediate superset the set Party, which we can think of as being the set of all those individuals or organizations with which our organization engages in some way. This immediately excludes from the universe of discourse for Customer such things as dogs, cars, and also any persons or groups not able to enter into a legal agreement (which a customer relationship is). Now, to define what a customer of our enterprise is, all we need to do is to state the rule which picks out a subset from that universe of discourse. To accept a person or organization as a customer is to add a row to the enterprise's Customer table representing that person or organization. [MW>] I was once given as a definition of “Customer” “One who is recorded in on the Customer table”. Accurate, but not actually useful J …a customer of our enterprise is – a subtype of a Party with whom we have entered into a customer relationship, a relationship subject to conditions stated in our policy manuals and implemented in our code. Finding these definitions – which clearly can be done – is doing something a lot more concrete than talking to a group of SMEs with the objective of obtaining consensus definitions of such key terms as “customer”. [MW>] <snip> So we have steered away from the dragon of Wittgensteinian definitions, and reached the safe fortress of Aristotelian definitions. To wit: the category Customer (of enterprise X) is represented by a relational table (hopefully named Customer, or something like it). A relational table is a set. A set is a collection of set members drawn from a universe of discourse such that the members of the set satisfy a specific set membership criterion. That membership criterion is expressed in policy manuals, and in the rules expressed in code that determine whether or not someone will be added to the Customer table. Prescriptive ontologies come into play, on my view, when our objective is to construct higher-level ontologies, for example industry-level ontologies. For these higher-level ontologies to play the role of facilitating semantic interoperability across those industries, each enterprise subscribing to the industry-level ontology must realize that their responsibility is not to simply play lip service to the industry ontology. It is to begin the difficult work of adjusting their de facto ontologies, including the set membership rules for the sets represented as tables in their databases, so that those lower-level ontological categories – the ones corresponding one-to-one with their database tables, are consistent extensions of those higher-level ontologies. [MW>] I’ve developed this kind of ontology. It is not really quite as you describe. Generally industry ontologies are about supply chain integration, so they do not cover all of an enterprises data. What becomes most important is to identify the subset of the industry model that is relevant to your slot in the supply chain, and to be sure that you can map your enterprise model into and out of those parts of the industry model. That has more flexibility than a simple subset, your mappings may be from multiple tables, or a subset of one of your tables. The other key is to be able to incorporate into your data key industry level master data such as product categories and their specifications. This is the basic, boots-on-the-ground work that is required to make prescriptive ontologies a reality. But the foundation from which we must begin is what ontological commitments are in fact, right now, in place in individual databases. The prescriptive work of integrating these de facto low-level ontologies, however, is not simply a bottom-up process of supertyping the types we begin with. It is a process of working with a well-developed upper-level ontology as well as a set of de facto low-level ontologies, combining top-down guidance towards an ideal goal with real-world realizations of ontological categories that have been proven, over time, to actually work. [MW>] Yes, but when you look at the commitments/rules imposed by a database, you should also be questioning whether these are not imposed as an implementation convenience (changing what are really many-to-many relationships to one-to-many for example). Perhaps this is something of a Manifesto – a description of a research and a development program of work guided by strong theoretical commitments and also a commitment to objects and processes that are time-tested in the real world. I don't like the term “Manifesto”, simply because of its creaky 19th century feel. But I am proposing that we clearly distinguish descriptive from prescriptive ontologies, clearly recognize the importance of descriptive ontologies, and begin to formalize them in the manner described above.
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