Metaphor is a good Greek word which means “a carrying from one place to another.”  It is, originally,  an action, not a thing.  It is the operation which changes a word by a new association.  The Greeks thought of it as “transferring to one word the meaning of another.”

The Greeks were better at abstractions than the English, apparently, since the current usage of “metaphor” usually refers to the thing to which the original word is compared.

According to this research in my old, patched together on both sides of the spine, Greek Dictionary, then, metaphor is not something you can choose, as from a list (“Shall I call this state a ship?  Shall I call this life a hard road?”)

Shall I say that research may upset the apple cart?  My poetry may be in for metamorphosis – a change of form.