RE: SUO: More KIF-ified Ontology Content
Matthew and Pat,
I believe that you have both made some very important points.
Rather than criticizing the ideas I don't fully agree with,
I will comment on some that I like very much.
Then I'll present my preferred way of viewing things, which
allows for multiple viewpoints to coexist (even when they
couldn't be simultaneously asserted without contradiction).
>MW: It is my experience that indeed the things people argue about the most
>are at the highest levels, where as the day to day things people find easier
>to agree on, because we can point at things to see whether we mean the same
>thing or not. So for example, I doubt if any difficulty we might have on
>agreeing what we meant by "red" would have anything to do with whether we
>saw it as a property, that things could take up, or as a class whose members
>were states, either individuals, or temporal parts of individuals. I would
>expect the discussion to be around where the border was between red and
>other adjacent colours. So "red" can fit into different frameworks with
>different ways of understanding what being red means.
This is a very clear statement of a position, which I agree
with, but which is more often expressed in a more muddled way,
which I don't agree with. The simpler, more muddled, and
to my mind, more dangerous way is the following:
It is easier for people to agree on the lower-level
concepts than on the higher-level ones. Therefore,
the high-level concepts aren't important, and it doesn't
matter if we haven't done a good job on the top levels.
The point where I stop agreeing in such an enthusiastic way
is at the next sentence:
>MW: I would further expect
>to be able to translate between the different frameworks.
Pat has stated my concerns very nicely:
>PH: Obviously the interesting case is where they are referring to
>different concepts. But the difficult case is where A's concept
>cannot even be expressed in B's overall ontological framework, and
>vice versa.
I also like Pat's succinct summary of an important distinction,
which I use as one of the top three in my top-level ontology:
>PH: In the
>continuant/occurent way of thinking, one refers to existence *at a
>time*. This means that the four-dimensional entities simply do not
>exist in this ontology. A continuant is something which continues to
>exist through time and retains its identity through time, and is such
>that (this is the characterising property) all its parts are present
>whenever it is present. Thus a person is a continuant, since if I am
>here then all my parts are here (now), while a race, say, is not a
>continuant - it is in fact an occurrent - since it has parts which
>are temporally distinguished: it has a beginning, a middle and an
>end. The distinction is like that between a person (a continuant) and
>that person's life (an occurrent).
And this is a good summary of the problem:
>PH: Both occurrents and continuants 'map' into 4-d entities in the 4-d
>histories ontology, but there is no principled way there to
>distinguish them. The nearest you can get is to say that continuants
>have isotemporal parts while occurents have isospatial parts, but in
>the 4-d histories ontology one can cut 'parts' any way one chooses,
>including along boundaries which slant in time (ie which are
>'moving', as someone who thinks non-4-dimensionally would say.) And
>the defining criteria for the distinction in the other ontology is
>literally incoherent in the 4-d ontology, since *nothing* is such
>that all its parts are present whenever it is present: the 'whenever'
>here is meaningless in the 4d ontology.
>As evidence for the idea of a continuant in intuitive thinking,
>consider the claim that I am the same person I was 10 years ago. This
>is literally false in the 4-d ontology (it can be expressed there by
>saying that me-now and me-1990 are both slices of the me-history, but
>that raises the question of what distinguishes one history from
>another, since these are also both slices of completely unrelated
>histories) Statements like this seem to depend on the idea of
>something retaining its identity through time, even though its
>properties may change. This 'locus of identity' is what constitutes
>the basic idea of a continuant, I think.
To summarize:
1. Pat says that the 4-D viewpoint allows ways of cutting up
the universe that cannot be mapped into the viewpoint of
3-D plus time.
2. Matthew points out that it is easier to map the 3-D plus
time viewpoint into the 4-D viewpoint.
I agree with both, but only with the caveat that "easier" does
not imply "possible to translate each and every distinction
that anyone would ever want to make."
>>MW: Until recently I used as my baseline a viewpoint that said that there
>>were individual things like you, my car, classes, and associations, where
an
>>association is a relationship that understands that it lasts for a period
of
>>time. I have moved to a 4D approach, replacing individual things with
>>spatio-temporal extents, and associations with timeless relations. However,
>>I know very well how to take something from my old model and represent it
in
>>the new model, and vice-versa.
But Pat points out the problem some distinctions vanish in
the 4-D ontology, and I agree:
>I wonder if you really can do this, if you think hard about it. Ive
>been living within a 4-d ontology for a long time and mapping other
>ontologies to it, and what I find is that many distinctions simply
>vanish, rather than being 'translated'. This is fine with me, of
>course, but it tends to get the other folk a little upset, especially
>when they have written entire books about these distinctions. And in
>the other direction, I find that perfectly reasonable-seeming things
>in my ontology, like 'moving' (sloping in space/time) boundaries,
>simply cannot be admitted into the other ontologies without producing
>unacceptable confusions.
I also agree very strongly with the following:
>PH: I think that what seems to me to be overoptimism about the
> prospects of the SUO among some folk might arise from their failure
> to appreciate that such incompatible conceptualizations can even
> exist, let alone all have their uses.
I agree with Matthew's last sentence, but not the first one:
>MW: I have a simple attitude towards incompatible conceptualisations: they
>mean we do not understand the world around us. The world around us is not
>incompatible with itself.
There may be very good reasons for using incompatible
representations even when a single unified one is understood,
as Pat explained with his example of quantum electrodynamics.
I also believe that there are a very large number of other
examples that one could use, as I tried to explain in the
Knowledge Soup chapter of my KR book.
Although I agree with a great deal of what Pat says,
I would quibble with the following:
>PH: the
>world around us IS incompatible with itself, in that we have to use
>two incompatible ways of conceptualizing it in order to fully
>describe it. There is no single underlying theory of the world, and
>some of the best minds who have thought about the matter during the
>last century have concluded that there is no way to produce one.
On the contrary, quantum electrodynamics is a single coherent
conceptualization, and it is possible (at least in principle)
to use it to solve problems without breaking it apart in
incompatible ways. Unfortunately, for most practical
problems, QED is so computationally difficult that
different (and incompatible) simplifications are necessary
to get useful results in an acceptable amount of time.
I strongly agree with Pat's point:
>PH: I think that you believe that there is a single, universally
>acceptable, ontology, and that all others can be mapped into it. I
>think this will happen only when science stops.
But I still believe that there is something useful that we can
accomplish even before science stops. My best cut at what
that may be is summarized in the Knowledge Soup chapter of
my KR book. Summarizing even more briefly,
1. An open-ended lattice of theories, which could be extended
arbitrarily far to accommodate any possible way of
conceptualizing the world in any finite set of concepts.
A complete lattice would have to be infinite, but any
particular version that might be implemented at any one
time is finite. However, there is no restriction on what
anyone might add to it, given enough time, effort, and
ingenuity.
2. Methods for navigating the lattice to find theories that
are approximately true or "good enough" for many problems,
and with methods for revising and extending theories to
make them better adapted to solving new problems.
For more about the lattice of theories, see Section 6 of my
paper on processes and causality:
http://www.bestweb.net/~sowa/ontology/causal.htm
And by the way, I believe that causality is a very important
concept that is central to a large number of issues in the SUO.
But that is another topic.
John Sowa