Blake's Sublime Allegory, Essays on The Four Zoas, Milton, & Jerusalem, Edited by Stuart Curran & Joseph Anthony Wittreich, Jr. is an excellent book to add to your library or download to your computer. Of interest is Roger R. Easson's essay, Blake and His Reader in Jerusalem.
In attempting to assist Blake students in making sense out of Jerusalem, Roger Easson says that "Jerusalem may be read as a poem about the experience of reading Jerusalem; it is a poem which enjoins the reader to participate in the creative process." Easson uses Blake's metaphor of the Golden String to demonstrate that the reader is expected to break down his dependence of reasoning and analysis in trying to work his way through the labyrinth or Jerusalem.
"...recalling the string metaphor in the Theseus myth, where Ariadne shows Theseus how to escape from the labyrinth after he has killed the Minotaur - he is to wind up the ball of string he unwound as he entered. Traditionally, the guide gives the ball of string to the adventurer as he enters the confusion of the labyrinth. Here however, Blake hands the reader the end of the string, which is unwound, indicating that the reader is in the depths of the labyrinth already. In this case, though, to follow the mythic parallel to its conclusion, before the reader can wind up the ball of string, he must conquer his spiritual Minotaur, the selfhood. At that point, winding the string may, in fact lead 'in Heavens gate,/Built in Jerusalem's wall'; for he will then be traveling in the 'Spirit of Jesus' which is 'continual forgiveness of Sin.' If however the reader does not subdue the selfhood, then the essential task enjoined by the metaphor - the destruction of the Minotaur - is unfulfilled and the reader succumbs to the selfhood, leaving Jerusalem a literary puzzle without solution.
As we have noted before, Jerusalem mirrors the state of the reader; and if the reader is still dominated by the spectral reason when he attempts to thread his way through the verbal maze, then he will be led deeper and deeper into the enigma, into the darkness of Blake's allegoric night." ( page 314).
AMERICA, Plate 11
Easson's view is that Blake's aim is to transform the accusing, rational reader to the forgiving, faithful reader by altering his perception.
On our blog WILLIAM BLAKE: RELIGION AND PSYCHOLOGY we have often returned to the metaphors of Golden String from the 77th plate of Jerusalem. Read more.
Heaven's Gate in Jerusalem's Wall
Return to the Fount of Life
Door to Heaven
Following the String
The Gate in the Arlington Tempera