Semantics and pragmatics are two distinct aspects of communication that pertain, in different ways, to the meaning of a linguistic utterance or other form of communication. Meaning itself seems like a fundamental aspect of communication, most likely because we don't have to think about what something means. Yet upon closer inspection we see it is more complex and this is where semantics and pragmatics become relevant.

If communication takes place by signs, then we can note, as Augustine does, that it involves 'natural' and 'conventional' signs (Meier-Oeser 2011). Dark clouds on the horizon are signs of rain and flags, words, and many gestures are signs of nations and ideas because the people communicating with them have learned their conventional interpretations. This hints at the possibility that meaning has several dimensions. Why clouds signify rain and flags signify nations is different. Dark clouds in the sky are connected to the here and now. They are materially part of the rain that will come, and one could say that the rain itself causes clouds. Another example is a foot print, which is a sign of someone walking in a direction because it is the effect and the visible trace of someone's foot. Thus these signs have meaning because of their relationship to a space and time, a context, of their production. Flags, by contrast, and most words, are meaningful because they represent or 'stand for' a particular idea, and one can substitute for the other.

Here it is important to point out that many people probably would say that semantics is the study of the meaning of words. Historically this is true, in the sense that the study of semantics is a particular approach to communication which attempts to understand why it conveys meaning in the form of concepts by looking for an underlying abstract logic. However, it is my view that this is not an adequate definition of meaning itself, and for this reason, the field of semantics has always run into its own limits. Many forms of communication derive meaning from their context of use, and indeed one could argue that all instances of communication get some of their meaning in their context. Thus semantics as the study of meaning has always been incomplete without some attention to the pragmatic aspect of communication, that is, the degree to which every act of communication is at some level both a flag and a rain cloud.

There are many lingusitic forms which have no meaning except for their connection to the context of their utterance. Otto Jespersen calls these words “shifters” (2013 [1922]: 123) because the same form with shift in meaning depening on who is speaking and to whom one is speaking, as well as when and where. Pronouns are the chief example of this. The English words I and you, among others, depend on the context of utterance to refer to something. Demonstratives (this, that) also fall into this category.

Another important example of pragmatic is the indexicality of communicative form. This has been particularly influential in studies of the social use of language and communication and the study of culture's influence on language. An index is something which signifies an idea because it is physically contiguous with it, or in some usages of it, is simply associated with it. Hence, one's accent signifies indexically the origin of the speaker without referring to it. Variant sounds of an utterance, independently of the words they form, point to or index the speaker and, in an extended sense, the context of the utterance. Similarly, speaking styles (also known as registers) index the background and social status of the speaker. Doctors index their medical training by their habitual preference for polite-sounding technical jargon for ailments, and so on.

The concept of an indexical sign comes from the work of Charles Sanders Peirce and his trichotomy of signs: symbol, icon and index. Although the index in some ways resembles a “natural sign,” Peirce's aim was move beyond the binary opposition of natural and conventional to a more general account of meaning as a process.

Philosophers of language have been concerned with semantic meaning as part of a more general inquiry into the relationship between language and truth. J. L. Austin (1962) observed that there was a limit to this inquiry because there were many kinds of linguistic expressions which were neither true nor false, but still had meaning. He argued that one could, at least provisionally, separate truth-bearing statements, called constatives, from another class of speech, in which speech was an act. These he called performatives or speech-acts, because rather than representing a fact about the world, they performed an action. Performatives can be identified by their verbs: promise, bet, name, decree. In uttering these verbs one is performing the action they name. Thus the meaning of these statements is not whether or not the correspond to reality. Rather, Austin proposes that such speech-acts are either felicitous or infelicitous, that is to say, whether they are accepted as valid in a particular context.

As he develops his concept of performatives, Austin comes to realize that the distinct between constatives and performatives is not absolute, because many statements seem to be both. Many statements have an indirect meaning and so assessing them in relation to their truthfulness leaves out the extent of their message. Thus, he concludes that all statements have three different aspects:

• locutionary, the referential meaning of an utterance.
• illocutionary, the action performed by the utterance.
• perlocutionary, the effect of the speech-act.

Suppose people are gathered in a classroom, and a teacher says to no one in particular, “It's chilly in here.” While the locutionary aspect of the statement is eithe true or not, given the context, the illocutionary force of the utterance is also clear. This statement is also a type of speech-act, specifically, a request to 'close the window.' Such a request, if felicitous, may lead to an effect, that is, someone responding by closing a window.

Austin, John L. 1962. How to Do Things with Words: The William James Lectures, 2nd ed. Cambridge, Mass.: Harvard University Press.

Jespersen, Otto. 2013 [1922]. Language: Its Nature and Development. London: Routledge.

Meier-Oeser, Stephan. 2011. “Medieval Semiotics.” In The Stanford Encyclopedia of Philosophy, edited by Edward N. Zalta, Summer 2011. http://plato.stanford.edu/archives/sum2011/entries/semiotics-medieval/.

Parmentier, Richard J. 1994. Signs in Society: Studies in Semiotic Anthropology. Bloomington, Ind.: Indiana University Press.

Silverstein, Michael. 1976. “Shifters, Linguistic Categories and Cultural Description.” In Meaning in Anthropology. School of American Research Advanced Seminar Series. Santa Fe, NM: University of New Mexico Press.