It would be a mistake to assume that cognitive linguists uncovered the secret power of metaphor. At least two reasons contradict such an idea: firstly, there has always been a great deal of work on metaphor, and, secondly, the concept of metaphor has itself been expanded in cognitive research to encompass questions and fields of study which up until recently had been investigated by scholars who did not consider metaphor to be their principle focus of interest. Indeed, a wide variety of disciplines from grammar to comparative linguistics have now entered into the metaphor debate. In contrast to this loose or all-embracing definition of metaphor adopted in cognitive linguistics, much of the research into metaphor that has been done throughout history and which has continued to develop parallel to cognitive research has proceeded by maintaining a restrained definition; for many approaches, metaphor remains a rhetorical trope. Four main approaches can be discerned among the diverse theories which attempt to account for metaphor as a trope: (1) philosophical investigations, (2) linguistic approaches, (3) the poetic tradition and (4) the rhetorical tradition.

PHILOSOPHICAL INVESTIGATIONS

Let us begin with the philosophical account of metaphor. Philosophers, going back at least as far as Plato, have been intrigued by metaphor. This fact is, nonetheless, given a very biased treatment by cognitive scholars. Johnson, a philosopher at the University of Oregon, has steered the Lakoff and Johnson tandem from a linguistic towards an increasingly philosophical position as regards metaphor.