The phrase is first used by Keats in a letter to Richard Woodhouse, dated 27 Oct. 1818: “As to the poetical Character itself (I mean that sort of which, if I am any thing, I am a Member; that sort distinguished from the Wordsworthian or egotistical sublime; which is a thing per se and stands alone) it is not itself — it 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.” Keats defines his own poetic identity as a “chameleon poet” in direct contrast to Wordsworth whom he characterises as monumental and fixed, …
Editors. "Egotistical Sublime". The Literary Encyclopedia. First published 25 May 2006; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=315, accessed 25 April 2015.]