Editing Indexicality (section)

===Adaptation of Peircean semiotics===
{{Main|Semiotic theory of Charles Sanders Peirce}}
The concept of indexicality has been greatly elaborated in the literature of linguistic anthropology since its introduction by Silverstein, but Silverstein himself adopted the term from the [[Semiotic elements and classes of signs|theory of sign phenomena]], or semiotics, of Charles Sanders Peirce. As an implication of his general metaphysical theory of the [[Categories (Peirce)|three universal categories]], Peirce proposed a model of the sign as a triadic relationship: a sign is "something which stands to somebody for something in some respect or capacity."<ref>Peirce, C. S. (1897 [c.]). [http://www.commens.org/dictionary/term/sign On Signs] {{Webarchive|url=https://web.archive.org/web/20170619201752/http://www.commens.org/dictionary/term/sign |date=2017-06-19 }} [R]. MS [R] 798</ref> Thus, more technically, a sign consists of

* A ''sign-vehicle'' or ''representamen'', the perceptible phenomenon which does the representing, whether audibly, visibly or in some other sensory modality;<ref name="commens">''Commens Dictionary of Peirce's Terms'', [http://www.helsinki.fi/science/commens/dictionary.html Eprint] {{Webarchive|url=https://web.archive.org/web/20100822160927/http://www.helsinki.fi/science/commens/dictionary.html |date=2010-08-22 }}.</ref>{{rp|"Representamen"}}
* An ''object'', the entity of whatever kind, with whatever modal status (experienceable, potential, imaginary, law-like, etc.), which is represented by the sign;<ref name="commens"/>{{rp|"Object"}} and
* An ''interpretant'', the "idea in the mind" of the perceiving individual, which interprets the sign-vehicle ''as'' representing the object.<ref name="commens"/>{{rp|"Interpretant"}}

Peirce further proposed to classify sign phenomena along three different dimensions by means of [[Semiotic elements and classes of signs#Classes of signs|three trichotomies]], the second of which classifies signs into three categories according to the nature of the relationship between the sign-vehicle and the object it represents. As captioned by Silverstein, these are:

*''Icon'': a sign in which "the perceivable properties of the sign vehicle itself have isomorphism to (up to identity with) those of the entity signaled. That is, the entities are 'likenesses' in some sense."<ref name=shifters/>{{rp|27}}
*''Index'': a sign in which "the occurrence of a sign vehicle token bears a connection of understood spatio-temporal contiguity to the occurrence of the entity signaled. That is, the presence of some entity is perceived to be signaled in the context of communication incorporating the sign vehicle."<ref name=shifters/>{{rp|27}}
*''Symbol'': the residual class, a sign which is not related to its object by virtue of bearing some qualitative likeness to it, nor by virtue of co-occurring with it in some contextual framework. These "form the class of '[[Course in General Linguistics#Arbitrariness|arbitrary]]' signs traditionally spoken of as the fundamental kind of linguistic entity. Sign vehicle and entity signaled are related through the bond of a semantico-referential meaning"<ref name=shifters/>{{rp|27}} which permits them to be used to refer to any member of a whole class or category of entities.

Silverstein observes that multiple signs may share the same sign-vehicle. For instance, as mentioned, linguistic signs as traditionally understood are symbols, and analyzed in terms of their contribution to reference and predication, since they arbitrarily denote a whole class of possible objects of reference by virtue of their semantic meanings. But in a trivial sense each linguistic sign token (word or expression spoken in an actual context of use) also functions iconically, since it is an icon of its type in the code (grammar) of the language. It also functions indexically, by indexing its symbol type, since its use in context presupposes that such a type exists in the semantico-referential grammar in use in the communicative situation (grammar is thus understood as an element of the context of communication).<ref name=shifters/>{{rp|27–28}}

So icon, index and symbol are not mutually exclusive categories—indeed, Silverstein argues, they are to be understood as distinct modes of semiotic function,<ref name=shifters/>{{rp|29}} which may be overlaid on a single sign-vehicle. This entails that one sign-vehicle may function in multiple semiotic modes simultaneously. This observation is the key to understanding deixis, traditionally a difficult problem for semantic theory.