How is nobility of diction a source of the sublime as discussed by Longinus in On the Sublime?
Not every work is extraordinary. Longinus, in On the Sublime, has given detailed account of the sources that make any work of art sublime. Sublimity refers to greatness and excellence. One of the key things that make any work extraordinary is its "diction" (By diction, one means the words chosen for use in the work). Now, a writer can always choose one word over the other. In very simple terms, for example, the same situation will be described by two people using different words and sentences. Longinus asserts that a work whose diction is not grand and noble can never become sublime. The writer has to select elevated diction, suitable metaphors and similies, etc. and only then the work can acquire magnificance. Using a noble diction is not intuitive faculty and basically depends on a writer's rhetorical competence.