Hanks grades a number of expressions involving the word sea according to how metaphorical he finds them, but it is unclear how to generalize his methods. In the course of the text, he gives at least two different answers to the question of how one might measure the metaphoricity of a phrase.
The Frequency Measure of Metaphoricity
First, he suggest the absolute frequency of the phrase as a measure (p. 21). An area of research is thus perceived as relatively literal because the string as a whole is quite frequent. By contrast, an oasis of calm is quite metaphorical because infrequent.Hanks may have a point here, but it's difficult to tell, because he never submits any evidence that the statistic of interest is the absolute frequencies rather than the relative ones. It is true that area of research only accounts for about 0.1% of the 34,824 occurrences of area in the BNC, while the 6 occurrences of oasis of calm add up to 2.4% of the 248 occurrences of oasis.
But on the other hand, these numbers are seriously sensitive to paraphrase: if you include study and search into the analysis, the tally jumps from 43 to 168, i.e., a near quadrupling. For the oasis of calm, expanding the search to include silence, peace, quiet, tranquillity, repose, and serenity only yields 9 more hits, i.e. a growth of about 50%. It is thus not at all clear which of those numbers we should trust more, and which will be responsible for how we think.
study | work | research | research | concern | search | analysis | enquiry | |
area of … | 87 | 61 | 43 | 43 | 40 | 36 | 5 | 4 |
calm | peace | tranquility | serenity | silence | quiet | repose | |
oasis of … | 6 | 3 | 2 | 2 | 1 | 1 | 1 |
The Resonance Measure of Metaphoricity
Second, Hanks suggests that the degree of metaphoricity is determined by certain quality called "resonance," a concept he has picked up from Max Black (pp. 20, 22). Hanks writes:In the most metaphorical cases, the the secondary subject [source domain] shares the fewest properties with the primary subject [= target domain]. Therefore, the reader or hearer has to work correspondingly harder to create a relevant interpretation. At the other extreme, the more shared properties there are, the weaker the metaphoricity. (p. 22)The term "resonance" subsequently seems to be used as the inverse of "semantic distance" (p. 22), and a similarity-based prototype theory is taken for granted. Accordingly, he finds that an Antarctic oasis—an ice-free area on Antarctica—is slightly metaphorical because it deviates from the stereotypical cartoon oasis with palm trees etc. (p. 30–31).
Meaning and Personal Experience
I thought I should just cite the summary of cognitive metaphor theory that Hanks gives, because it succinctly sums up some of the concerns that a number of people have had about it:Lakoff and Johnson's basic thesis about metaphor is that its function is to enable us to interpret concepts (especially abstract concepts) in terms of familiar, everyday cognitive experiences. This is broadly satisfactory, though we might be tempted to substitute 'perceptual experiences' for 'cognitive experiences', and common sense forces us to acknowledge that the 'everyday experience' in question is that of the language community at large, not each individual. (p. 19–20)In fact, I don't think a metaphor needs to be grounded in anybody's first-hand experience in the general case; and metaphors that involve dying are good illustrations of this phenomenon.