This term was introduced by the poet John Keats in a letter
written December 1817 to define a literary quality :
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.
He goes on
to criticize Coleridge for not being 'content with half knowledge'; and in
later letters complains of the 'egotistical' and philosophical bias of
Wordsworth's poetry. By negative capability, then, Keats seems to have meant a
poetic capacity to efface one's own mental identity by immersing it
sympathetically and spontaneously within the subject described, as Shakespeare
was thought to have done.