Dan Sperber and Deirdre Wilson make two strong claims in Relevance. The first is about cognition, and the second about communication:

  1. Human cognition tends to be geared to the maximization of relevance.
  2. Every act of ostensive communication communicates a presumption of its own optimal relevance. (260)

Sperber and Wilson assume that utterances are interpretations of the mental states of speakers which are entertained by listeners as either interpretations or descriptions, decoded along a Porphyrian tree to determine if they are actual or desirable either as representations or actual states of affairs (232). Interpretations of propositions such as “I make $200 a day” are not evaluated for their truth value in order to ascertain if it an actual state of affairs, but rather we take it for granted that the figure may be inexact and that the speaker may instead make $192.50 instead. It is likely that we will offer an “optimally relevant” simplification rather than communicate longwinded facts. They propose that metaphor works in much the same way.

Sperber and Wilson suggest that processing “Bill is the nicest person there is” (106a) proceeds along the same lines as “This room is a pigsty” (88):

Moving along to a marginally more creative example (107) is a fairly conventional metaphor whose interpretation involves bringing together the encyclopaedic entries for Robert and bulldozer, which do not normally come together in a subject-predicate relationship:

(107) Robert is a bulldozer.

The result will be a wide array of contextual implications, many of which, being contradictory, can be automatically discarded. The relevance of (107) will be established by finding a range of contextual effects which can be retained as weak or strong implicatures. Here there is no single strong implicature that automatically comes to mind, but rather, a slightly weaker, less determinate range having to do with Robert’s persistence, obstinacy, insensitivity and refusal to be deflected. The hearer has to take a slightly greater responsibility for the resulting interpretation than he does with (106a) and (88).

In general, the wider the range of potential implicatures and the greater the hearer’s responsibility for constructing them, the more poetic the effect, the more creative the metaphor. A good creative metaphor is precisely the one in which a variety of contextual effects can be retained and understood as weakly implicated by the speaker. (239)

In Sperber and Wilson’s view, metaphor and other tropes “are simply creative exploitations of a perfectly general dimension of language use” (237). Their framework is fairly persuasive in its flexibility. If communication is assumed to be propositional in nature, then hybrid contextually dependent “events” can also be explained. For example: Robert walks into a room, knocking over all the furniture in his path. The speaker points at Robert and says “Bulldozer!” Having only a single term, this would be difficult to analyze as a textual or linguistic metaphor. Taken as a proposition (assuming the utterance is relevant to the “framing” situation) which is not overtly stated, but rather, implicated then its analysis as an instance of metaphoric labeling is possible. However, this is not a case where Robert has been “named” as “Bulldozer” but rather one where his performance mimics the nominative label. The utterance expresses an actual similarity, a description, as much as it does an interpretation. It is in this that we see the primary difficulty with Sperber and Wilson’s framework. Can propositional acts of communication be segregated into categories of description vs. interpretation, or actual vs. desirable? In many communicative situations the boundaries do not seem clear. Constructing examples to demonstrate relevance presumes relevance, rendering Sperber and Wilson’s framework a tautology.

Sperber and Wilson’s conclusion that metaphor requires “no special interpretive abilities or procedures; it is a natural outcome of general abilities and procedures used in verbal communication” would not be disputed by most metaphor theorists. Many, George Lakoff in particular, would claim that metaphor, rather than relevance, is the “primary principle” of both cognition and communication. The central problem of this claim is defining precisely what metaphor is and how it works. Framing the question as a purely linguistic one—where metaphor is a comparison between two terms, or between a focal term and a “frame”—does not establish metaphor as a property of cognition, but only as a matter of communication. Addressing the cognitive properties of metaphor to differentiate it from relevance must transgress the boundaries of linguistic demonstration.

* I couldn’t help but think about an Iggy Pop song from Zombie Birdhouse while I was trying to write this:

Like a giant clam
Run that girl over
Get that poseur

Of course, that’s a simile and not a metaphor� and a rather shaky one at that.