- From: Pat Hayes <phayes@ihmc.us>
- Date: Mon, 9 Jul 2007 16:09:08 -0500
- To: ht@inf.ed.ac.uk (Henry S. Thompson)
- Cc: www-tag <www-tag@w3.org>
>-----BEGIN PGP SIGNED MESSAGE----- >Hash: SHA1 > >I'm going to try a new tack on the terminology discussion, drawing as >best I can on all the useful work that's been done in the preceding >Terminology thread [1], which has been very helpful in teasing out the >issues with the TAG's terminology, particularly as manifested in >WebArch [2]. > >This is the first in a series of messages in which I want to try to >synthesise and summarise, without necessarily explicitly following up >on specific previous posts, trying to build up slowly, checking that >we have common ground at each step. Good plan :-) > >My basic goal is to set out my understanding of the relevant words and >phrases from the philosophy of language and related disciplines, and >explore their application to the Web. A side remark: I have a lingering worry that to even try to use philosophy-of-language terminology when discussing the Web specifically is to give the Web rather too much importance in the grand scheme of things. It seems to me that the Web is really only a new publishing/distribution/communication medium, at bottom. Its not a new way of using language. It uses language the way that language has always been used, pretty much; and we might all do somewhat better to admit this up front and stick to talking about actual architecture. But now Ive put this worry on the table I will try to not let it overly color my remarks. >Along the way, I'll try to >connect up with the specific terms and usages of WebArch. > >Aside from the obvious point that people, particularly people with >familiarity with the philosophical terminology in this area, have had >problems with WebArch's usage, and we should try to fix this, I have >another reason for stepping back and attempting this review: there is >something special about computational systems (including, but not >limited to, the Web) in this space, as pointed out by Noah Mendelsohn >in his contribution to this thread: such systems not only >manipulate symbols which function as names, they often actually get >behind the names in a way which is pretty much unprecedented. I'm >curious to see how this stresses the traditional philosophical >perspective. I agree with that point (and I suspect we will both acknowledge Brian Smith's influence on our views here.) But again, this doesn't seem to me to be a matter particularly well illustrated by the Web, which is more centrally concerned with moving information around than with the semantic grounding of actual computation. > >Consider a computer program which simulates an automobile engine. >Stipulate that it has a variable named 'waterTemp', which, we might >say, denotes the (simulated) water temperature in the (simulated) >radiator of the (simulated) engine. We might find in such a program >some such statement as > > waterTemp = ( waterTemp + engineBlockTemp ) / 2 ; > >which we can understand as saying that at each step in the simulation, >the water temperature is updated by averaging it with the temperature >of the engine block. So far, so good -- the symbols in the program >are being used just about exactly the same way that the phrases "water >temperature" and "temperature of the engine block" are in ordinary >language, that is, they are being used as referring expressions, or >names. > >But in the case of the computer program, they are actual something >more -- when the program actually _runs_, they are causally connected >to the actual (binary representations of) the (simulated) >temperatures. The above program statement, when exectuted, actually >_changes_ the (simulated) water temperature. > >And this sort of thing is not restricted to simulations Quite. Make it into an engine controller and the variable be the fuel flow rate, for example. >-- when I go >online to my bank and pay my electricity bill, there is, >oversimplifying of course, a statement in a program which reads > > balance = balance - billPayment ; > >When _that_ statement is executed, my _real_ bank balance changes, >courtesy of a change in the (binary representation of) the number >named by the symbol 'balance' in the context of that program. > >(I said above that this causal connection between name and denotation >is pretty much unprecedented in natural language -- there is at least >_one_ precedent, namely what speech act theory calls 'performative' >utterances. When the registering officer says "I pronounce you man >and wife", the world changes. I'm not sure to what extent this >illuminates the issues at hand. I think that is rather different. It only works because of a social convention linking special speech acts to various (non-physical) states such as being married. If he had said "I now pronounce you three inches taller" it wouldn't have worked at all. We can have speech acts on the Web as well, in fact I think they would be a good idea (see section 8.3 in http://www2005.org/cdrom/docs/p613.pdf) >) > >OK, back to the beginning. Following the informal precedent of this >discussion so far, I'll use prefixes to mark technical terms with >their owners, so, e.g. pl:denote for 'denote' per Philosophy of >Language, webarch:identify for 'identify' per WebArch, >la:depict for 'depict' per Goodman's _Languages of Art_ [3] and >vsr:expression for 'expression' per Cantwell Smith's "Varieties of >Self-Reference" [4]. Oh, that last one is rather a tricky source for such a bland word. > >pl:referring_expressions, in particular pl:names, pl:denote >pl:referents. pl:proper_names approximate pl:rigid designators, which >have exactly one pl:referent. Some pl:referring_expressions, known as >pl:indexicals, may have different referents depending on the context >of use, for example 'I', 'over there', 'next Thursday'. One response >to this is to distinguish pl:meaning from pl:interpretation, >describing pl:meaning as a mapping from pl:context to >pl:interpretation, where it is pl:interpretations (of names >respectively sentences) which are pl:referents or have truth values. >Thus when two disputants each say "I'm right, you're wrong", their >utterances have the same pl:meaning, but distinct pl:interpretations, >of which at most one is true. > >How the relation between pl:proper_names and their pl:referents is >established, transmitted and maintained is the subject of considerable >debate, but one currently popular position associated with Kripke [5] >distinguishes categorically between pl:proper_names and other >pl:referring_expressions, appealing to a notion of original pl:baptism >for the former alone. > >So far so good -- I think we can establish some uncontroversial >parallels: > > pl:proper_name == webarch:URI > pl:denote == webarch:identify > pl:referent == webarch:resource I don't find ANY of these even plausible, let alone uncontroversial. A URI is like a proper name?!? In what possible sense? How can one make any sense at all of the notion of an ontology all of whose names are proper names?? And (sorry to be so persistent, but) if webarch:identify means pl:denote, then why is there anything at all in the webarch document about http? Almost all of that document is about topics which have nothing to do with pl:denotation; so what justifies this equation? The last equation is categorically wrong, since 'referent' isn't really a category: it refers to something at one end of a relationship, which can in fact be anything at all. >Both sides of this set of equations gloss over the >pl:meaning/pl:interpretation distinction, although in slightly >different ways. "John Smith" is actually a pl:indexical, and needs a >context to uniquely determine a pl:referent, whereas webarch:resources >can themselves _be_ pl:indexical -- WebArch would say that _the_ >webarch:resource webarch:identified by http://www.guardian.co.uk/ is >something like "the current front page of the Manchester Guardian". As I understand the REST architectural model, the actual resource is the *function* from times to the MG front page at that time. Then you don't have to say its indexical, which probably makes the whole theory simpler. > >So wherea the pl:meaning of a pl:referring_expression is a function, >and thus something quite different in kind from most pl:referents, >webarch:resource does double duty, corresponding to both pl:meaning >_and_ pl:interpretation in a more careful set of equations: > > pl:proper_name == webarch:URI > pl:denote == webarch:identify > pl:meaning == webarch:resource > pl:interpretation == pl:referent == webarch:resource > >It's also worth noting that some URIs are more like pl:proper_names >than others -- there's a sort of continuum determined by URI scheme, >with uuid: at the most rigid end, ftp: and http: in the middle, and >mailto: being a bit off to one side. . . > >Finally for this first message, note that there is another >correspondence which I think obtains: > > pl:baptism == [webarch:minting] ([2] itself doesn't actually have a > term for this, but minting is commonly > used in discussion of the Web ) > >In both cases the person who first 'utters' a name has the authority >and takes the responsibility for determining the >pl:referent/webarch:resource it will thenceforth >pl:denote/webarch:identify. Ah, but (very important point) to take responsibility for baptizing isn't to actually baptize. There isn't anything in the webarch: domain corresponding to pl:baptizing, in fact: a central lack in the Web world picture that Ive been complaining about for years. If we had some unambiguous and standard way of *saying* what URIs actually mean/denote, then we could require minters to do their own baptizing. Named graphs were one idea on this direction. AFAIK, its still the only proposal for a convention which would actually baptize a URI, in the sense of determining its referent; if you prefer, making it into a real proper name. > In both cases such authority may be >exercised felicitously or spuriously. Right now it can't be exercised at all. There aren't any suitable ceremonies to exercise it in. Pat > >ht > >[1] http://lists.w3.org/Archives/Public/www-tag/2007Jun/0056.html >[2] http://www.w3.org/TR/webarch/. >[3] Goodman, N., _Languages of Art: An approach to a theory of > symbols_, second edition, Hackett Publishing, 1976. >[4] Cantwell Smith, B., "Varieties of Self-Reference," in Joseph > Halpern, ed., _Theoretical Aspects of Reasoning about Knowledge_, > Morgan Kaufmann, 1986, pp. 19-43. >[5] Kripke, S., _Naming and Necessity_, Cambridge, MA: Harvard University > Press, 1980. >- -- > Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh > Half-time member of W3C Team > 2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440 > Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk > URL: http://www.ltg.ed.ac.uk/~ht/ >[mail really from me _always_ has this .sig -- mail without it is forged spam] >-----BEGIN PGP SIGNATURE----- >Version: GnuPG v1.2.6 (GNU/Linux) > >iD8DBQFGklEskjnJixAXWBoRAqA7AJ9EmzZgiyiGF1VInsyIsR3crXe5RwCdFz4A >mAaQaYUrjjIUCXWTHJB/+ms= >=VJCb >-----END PGP SIGNATURE----- -- --------------------------------------------------------------------- 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
Received on Monday, 9 July 2007 21:09:17 UTC