Even the word metaphor is a metaphor about carrying things across
Call a window by its old name and you get wind eye, a buried image hiding in an everyday word. The term metaphor is itself one of these: it comes from Greek for a transfer of ownership, and it describes lifting a word out of its home territory and setting it down somewhere new.
A metaphor names one thing by pointing at another, inviting a comparison between ideas that normally have nothing to do with each other. It differs from a simile in how openly it works. A simile announces the comparison with like or as, while a metaphor simply asserts that the two things match on the relevant point, which is why it usually lands harder. Shakespeare's claim in As You Like It that the whole world is a stage is the classic English example; nobody thinks people are literally actors, yet the image says something about how lives unfold.
Scholars have built plenty of vocabulary to take metaphors apart. In 1936 the rhetorician I. A. Richards split them into a tenor, the thing being described, and a vehicle, the thing lending its qualities. So in the stage line, the world is the tenor and the stage is the vehicle. Other writers prefer ground and figure, and cognitive linguists speak of target and source.
The psychologist Julian Jaynes went further, inventing the words metaphrand and metaphier, along with paraphiers, the extra associations a vehicle drags along. Say someone is a tornado and you import power, wind, danger and spinning motion. One listener hears destructiveness; another hears a person who spins out of control, a fresh image that suits humans better than weather. Jaynes argued metaphors can expand what we perceive and even create new objects of thought.
The philosopher John Searle challenged the idea that every metaphor is just a shortened simile. Calling Sally a block of ice seems to mean she is rigid and cold, but those words are figurative too, so the comparison never bottoms out in plain literal fact. Ancient texts show how old the habit is: the Psalms, dated to around 1000 B.C., call God a rock and a shepherd.
Source: Metaphor
