From Greek deixis "reference, indication". (Oxford English Dictionary)
The terms deictic and deixis are roughly equivalent to indexical and indexicality, but are of much earlier origin. They are borrowings of Greek deiktikos and deixis, which go all the way back to Dionysius Thrax and Apollonius Dyscolus — that is, to the very beginnings of Western grammatical theory.
Lyons (1977) Ch. 15 gives a brief discussion of the history of these terms, pointing out that the early Greek authors used them just for demonstrative pronouns and articles. Latin grammarians used dēmonstrātīvus in the same sense, eventually yielding English demonstrative. Modern linguists have come to use deictic for a broader class of examples, so that deictic and demonstrative no longer function as synonyms. Lyons does not identify or date the steps in this expansion of meaning, and I have not attempted to do so either. However, I can report that nineteenth and early twentieth century examples do not seem to exhibit much expansion beyond demonstratives, so any major broadening would seem to be more recent.
Although deictic and indexical are often described as synonyms, there is a difference in the ways these terms are often used, which I noticed quite some time ago, but have not seen commented on by other authors. Theorists using the term indexical tend to approach the topic of context-dependence as an issue in how reference is determined. For example, what day does one refer to when using the word yesterday? It depends on the context of utterance: On February 22, one refers to February 21, and on February 21, one refers to February 20, etc. Theorists using the term deictic sometimes approach it in the same way, but often approach it instead as in issue in how word choice is determined. For example, given that you want to refer to February 21, what word do you use? It depends on the context of utterance: On February 21 you use today, on February 22 you use yesterday, on February 20 you use tomorrow, etc.
For a case like yesterday, these two approaches seem like two sides of the same coin. They both assume that context and word choice determine reference; the difference is just in whether we think of the context and word choice as given, so that we have to "solve for" reference, or instead think of context and reference as given, so that we have to "solve for" word choice.
But the way one approaches a topic like context-dependence can have a big effect on what kinds of examples one looks at, and as a result, a variety of examples have been discussed under the heading of deixis that have received little or no discussion under the heading of indexicality. "Social deixis" provides a salient class of such examples. In French, a speaker addressing a particular person has the option of using using either of two second-person pronouns: tu or vous. The choice depends on features of the context, particularly on the social distance between the speaker and addressee, and their relative positions in social hierarchy. Likewise in English, a speaker who refers to a particular person has the choice of using the first name, or the last name and title, the choice depending on the social distance and relative position in social hierarchy of the speaker and referent.
Approached as a matter of word choice, the context-dependence in such examples is obvious. Approached as a matter of reference determination, it is much less so. One would have to consider relatively unusual cases, in which there is more than one plausible addressee, or more than one person with the same name to whom the speaker might be referring, before the role of social distance and hierarchy in determining reference became apparent. As a result, such examples have received a good deal of attention in the "deixis" literature, but very little in the "indexicality" literature.
As far as I know, Charles Fillmore's (1971) Santa Cruz Lectures on Deixis, published as Fillmore (1997), provides the first use of the term social deixis. Undoubtedly, these lectures were also a major factor in establishing the "word choice" perspective on deixis, as the factors governing the choice between the verbs come and go (and related pairs like bring and take) are a recurrent theme.
References
- Apollonius Dyscolus (2nd c. CE) Peri antonymias.
- Dionysius Thrax (2nd c. BCE) Tékhnē grammatikē.
- Fillmore, Charles (1997) Lectures on Deixis. CSLI Publications.
- Lyons, John (1977) Semantics, vol. 2. Cambridge University Press.
