taking Keats at his word. . .
"....several things dovetailed in my mind, & at once it struck me, what quality went to form a Man of Achievement especially in Literature which Shakespeare possessed so enormously -- I mean NEGATIVE CAPABILITY, that is when man is capable of being in uncertainties, Mysteries, doubts, without any irritable reaching after fact & reason -- " ~John Keats
JK clarifies what he means by the term immediately: the ability to be in Mystery, etc. without needing a rational explanation of it (like Coleridge and Wordsworth clung to). I was always amazed at how few scholars took what JK said seriously; instead, they'd try and complicate, or explain what couldn't be explained: truth, beauty, the holiness of the heart's affections, imagination, love . . .
Keats instinctively lives the transrationality of gnosis, which requires creative passivity as a receptivity toward knowable mystery. Indeed, Keats is the most mystical of the Romantic poets in terms of valuing positively the self-affirming emptiness necessary to Gnostic insight. In a letter to J. H. Reynolds of February 1818, he writes in a colourfully metaphoric style:
"Now it is more noble to sit like Jove than to fly like Mercury - let us not therefore go hurrying about and collecting honey-bee like, buzzing here and there impatiently from a knowledge of what is to be arrived at: but let us open our leaves like a flower and be passive and receptive . . . I was led into these thoughts, my dear Reynolds, by the beauty of the morning operating on a sense of Idleness. . ." (L 1:232, 19/2).
Here Keats derides the aggregative content of objective knowledge which contrasts with the lived oneness of knowing and being. In the same letter he speaks positively of the 'diligent Indolence' of contemplation, as well as of the great benefit to humanity achieved through the 'passive existence' of 'great Works'.
As has been mentioned, Keats' predisposition toward receptive intuition is evident in his description of poetic 'Negative Capability' as the ability to be 'in uncertainties, Mysteries, doubts, without any irritable reaching after fact & reason' (L 1:193, to George and Tom Keats, 27(?)/12/1817).
This is not T. S. Eliot's 'Impersonal Theory' of poetry, which depicts the poetic self as catalytically detached and inert - a mere mediator of poetry through an 'escape' from personality. Eliot is here describing an 'escape from emotion' as an unambiguous self-extinction which would be inconceivable to Keats.
Keats asserts the positive capability of negative knowledge through an oxymoronic correspondence between dark and light. In the 1818 sonnet 'To Homer', the poet depicts in lines 9 to 12 the paradox of knowing ignorance in terms of the thematic harmony of mind and Nature as a symbolic union of dark and light:
Aye on the shores
of darkness there is light,
to negative capability List