Keats' concept of negative capability was one of the most philosophically profound elements of both his work and Romanticism, in general. Essentially, the concept argued that there is something beautiful and acceptable in living with the unknown. This idea flies in the face of the Neoclassical Enlightenment belief systems that preceded Romantic thought. It suggests that there is a beauty about that which is unknown and that not everything in consciousness requires a direct and absolute answer. Keats saw consciousness as something in which negative capability played a major role. Consider how Keats felt about the poet's need to convey this to the audience, defining negative capability in terms that would make an empiricist stammer at its lack of totality:
capable of being in uncertainties, Mysteries, doubts, without any irritable reaching after fact & reason…
For Keats' and his poetry, exploring this domain was extremely important. No better is this seen than in his closing couplet to "Ode on a Grecian Urn." The idea of "all ye need to know" is something rooted in negative capability, learning to live within limits of one's state of being in the world. Interestingly enough, this helps to set the stage for Modernist thought, which takes the idea of negative capability to its logical conclusion in its suggestion that everything is subject to negative capability.