From Walt Whitman’s essay “Slang in America,” :
Slang, profoundly consider’d, is the lawless germinal element, below all words and sentences, and behind all poetry, and proves a certain perennial rankness and protestantism in speech. As the United States inherit by far their most precious possession–the language they talk and write–from the Old World, under and out of its feudal institutes, I will allow myself to borrow a simile even of those forms farthest removed from American Democracy. Considering Language then as some mighty potentate, into the majestic audience-hall of the monarch ever enters a personage like one of Shakspere’s clowns, and takes position there, and plays a part even in the stateliest ceremonies. Such is Slang, or indirection, an attempt of common humanity to escape from bald literalism, and express itself illimitably, which in highest walks produces poets and poems, and doubtless in pre-historic times gave the start to, and perfected, the whole immense tangle of the old mythologies. For, curious as it may appear, it is strictly the same impulse-source, the same thing. Slang, too, is the wholesome fermentation or eructation of those processes eternally active in language, by which froth and specks are thrown up, mostly to pass away; though occasionally to settle and permanently chrystallize.
Biblioklept 