How we change what others think, feel, believe and do
The Compact Oxford English Dictionary defines 'metaphor' as:
1 a figure of speech in which a word or phrase is applied to something to which it is not literally applicable (e.g. food for thought).
2 a thing symbolic of something else.
Wikipedia describes a metaphor as:
...a rhetorical trope where a comparison is made between two seemingly unrelated subjects. Typically, a first object is described as being a second object. In this way, the first object can be economically described because implicit and explicit attributes from the second object can be used to fill in the description of the first.
More simply, this means using one thing to describe another thing. (a 'rhetorical trope', by the way, basically means 'using words where their meaning is changed', also known as a 'figure of speech').
'Metaphor' comes from the Greek word metapherein, meaning 'to transfer'.
Uh oh! I'm toast.
I was blown away!
He was trying to bait me.
She's just a pussy cat.
The cells were in the bowels of the castle.
The value of a metaphor is in the meaning that it can create. Meaning happens inside the mind and as such is an individual experience. Nevertheless, the commonality of words means that the well-understood meaning of one world can associated with a concept that is not so well understood or where new meaning need to be injected.
Metaphors are representations, in that they represent an idea but are not the idea in itself. All words are also representations, and in this sense all words are metaphors. We do not directly experience reality, but rather an internal symbolic representation of an external 'real'.
In prosody, metaphoric equating of dissimilar objects is sometimes called discordia concors.