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Poetry is the most intense and muscial expression of language.
There are two ways that language may be intensified: wit and metaphor. Wit refers not just to being funny, but to the unexpected character of human intelligence as opposed to the simple communications of animals or the complex but rigid "language" of "robotic intelligence".
Central to human wit is the use of metaphor in which an idea, an abstraction, is compared to an image, an object, an event or an experience, in such a way that the idea is clarified and the image is enriched.
Great poetry requires exact analysis of inwardly recognized metaphors. Although this analysis cannot be carried out with scales and rulers, it uses logic, wisdom, and carefully observed interior and exterior experience, and it thereby attains precision. This poetic necessity of exactitude is the reason we say that readers and writers of Poetry must use both the analytic mode [such as diagrams!!] and the intuitive mode of thought.
In poetry, musical elements such as meter, rhythm, rhyme, assonance -- give a kind of body to the thought. The best prose and the best poetry share many elements of depth, beauty, and intensity, but when properly-conceived musical elements support the meaning within a poem, it always has the edge as powerful language, for it more fully addresses the human person who lives in the world with mind and body.