Being far more than a decorative literary device, Metaphor, is one of our most often used and effective ways of knowing. The power of a good metaphor far exceeds that of a simple word or a careful drawing. Indeed, every once in a while we could be amazed by someone who come up with one extremely simple but intuitively elegant metaphorical analogy to describe another situation which looks dissimilar but shares critical attributes with the one in the new sense. That is a moment of a great enlightenment. As Aristotle wrote, in De Poetica,
"The greatest thing by far is to be a master of metaphor; it is the one thing that cannot be learnt from others; and it is also a sign of genius, since a good metaphor implies an intuitive perception of the similarity in the dissimilar."