Figures of Speech: Metaphor
Metaphors
All metaphors can be analyzed and reduced to the equation "X equals Y." Examples in everyday languge abound. The expression, You are the sunshine of my life equates someone's beloved with sunshine; something that is impossible in literal terms unless that person becomes a ball of nuclear fusion. The expression candle in the wind likens life's fragility to an extinguished candle.
Metaphor is one of the most common figures of speech and many words have their origin in metaphor. When a metaphor is so common that people usually take it for granted, it is called a dead metaphor. Understanding, for example, is a dead metaphor, having its origins in the idea that "standing under" something was akin to having a good grasp of it (another, slightly less dead metaphor) or knowing it thoroughly.
Metaphors are seen as very powerful tools because they allow for the expression of abstract principles by reference to concretes. They can also be dangerous to understanding, in that people may fail to recognize the figurative nature of a metaphor, and come to take it literally. On the other hand, since so many, many words are dead metaphors, attempting to avoid them entirely would end in silence. For instance, consideration is a metaphor meaning "take the stars into account", mantel means "cloak or hood to catch smoke", gorge means throat, and so forth for thousands more.