Holt, D. Lynn.  "Metaphors as Imaginative Propositions."  Process Studies 12, no. 4 (Winter 1982): 252-6.

Abstract

The article represents an attempt both to situate "irreducible" metaphor within the categoreal scheme of A.N. Whitehead's philosophy and, once situated, to show what contribution this philosophy may provide for contemporary discourse about metaphor and philosophy of language in general.  The conclusions are: metaphor is a verbal approximation of a species of imaginative propositions; and, 1) coupling with a notion of "inverted abstraction," and 2) language is most determinate when it is most general.  [Abstract from The Philosopher's Index]