The Talmud says that for every concept, King Solomon had three thousand metaphors.

Chasidus explains that these metaphors weren't parallel tracks for explaining the same idea.  The three thousand metaphors weren't horizontal but vertical -- one stacked on top of the other.

In other words, King Solomon could take a lofty concept that was totally removed from other people's capacity to understand and bring that self-same concept down three thousand levels until anybody could grasp it.

About a millenium later, the Sage, Rebbe Meir, was said to be able to come up with three hundred metaphors for every concept.  That means that he could get anybody to understand a concept that was three hundred levels beyond that person's intellect.  That's only a tenth as far as King Solomon was able to go, but it's still pretty impressive. 

Metaphor is the intellectual, verbal art of making the abstract accessible.  It means teaching us something that we are unable to relate to by comparing it to something that we already relate to.  More aptly stated, a metaphor solidifies for us a lofty idea by pointing to how that very concept is manifest on a lower plain of reality.  The one who is proficient in the art of metaphor uses the language of our experience of the mundane world as a platform upon which to build for us a scaffolding to the sublime.

A good metaphor lifts us to intellectual heights to which we could not even dream of, let alone reach, on our own.

A good metaphor takes us up, above and beyond what we could normally understand.

A good metaphor.

What's a bad metaphor?

One that uses lofty terms to describe what is course and crass.

One that brings us down.