Wikipedia 10K Redux by Reagle from Starling archive. Bugs abound!!!
A figurative use of language that is used to paint one concept with the attributes normally associated with another. For example, "ship of state" is a metaphor that likens the government to a ship: just as a ship needs a captain to make decisions, give orders, and control things, so a government needs someone to make decisions, give orders, and control things. By refering to the "ship of state" one emphasizes this aspect of government. Metaphors are very powerful tools because they allow for the expression of very abstract principles by reference to conretes. 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.