- From: Henry S. Thompson <ht@inf.ed.ac.uk>
- Date: Mon, 09 Jul 2007 16:15:56 +0100
- To: 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. 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. 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. 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 -- 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.) 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]. 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 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". 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. In both cases such authority may be exercised felicitously or spuriously. 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-----
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