Be ye therefore perfect. (Matthew 5:48)
In the Preface to The Great Divorce C. S. Lewis wrote:
"if we accept Heaven we shall not be able to retain even the smallest and most intimate souvenirs of Hell." We may have to give up our right hand or our right eye.
Egocentricity, Self-centeredness, Narcissism, Selfishness, contempt for the 'neighbor', etc. etc! These are some of the attributes that Blake grouped together into the image of "The Selfhood". Blake saw these and other similar traits within himself; he saw them in others, and he saw them in the world.
For twenty years he fought injustice, greed, chicanery, deceit, exploitation; in all those things he was very much of a negative thinker. But at some point he turned: he was forgiven; he turned positive although he understood all too well that he, we, the world must annihilate the Selfhood in order to reach Eternity.
Blake also used the term 'Spectre'; it too was to be annihilated.
In the poem, Milton, we hear from the mouth of 'Milton' speaking to his Spectre:
"Such are the .......Laws of Eternity, that each shall mutually
Annihilate himself for others' good, as I for thee. . . .
In Self annihilation all that is not of God alone,
To put off Self and all I have, ever & ever . . ." (Milton plate 39; Erdman 139)
And "The Negation is the Spectre, the Reasoning Power in Man:
This is a false Body, an Incrustation over my Immortal
Spirit, a Selfhood which must be put off & annihilated alway. " (Milton 40; Erdman 142)