"The emphasis on shifting essences, uncertainty, and fiercely contrasting opposite states was, of course, neither new nor unique to Byron. He and the other Romantic poets, however, took the ideas and emotions to a particularly intense extreme. Shelley's belief that poetry "marries exultation and horror, grief and pleasure, eternity and change," and that it "subdues to union, under its light yoke, all irreconcilable things," was in sympathy not only with the views of Byron but those of Keats as well. "Negative capability," wrote Keats, exists "when a man is capable of being in uncertainties, Mysteries, doubts, without any irritable reaching out after fact & reason." The "poetical Character," he said: has no self-it is every thing and nothing-It has no character-it enjoys light and shade; it lives in gusto, be it foul or fair, high or low, rich or poor, mean or elevated-It has as much delight in conceiving an Iago as an Imogen. What shocks the virtuous philosopher, delights the camelion Poet. It does no harm from its relish of the dark side of things any more than from its taste for the bright one; because they both end in speculation."