but Jerusalem is not initially a hymn. It's the opening to Blake's epic prophecy 'Milton', which is categorically not an orthodox poem, in which in fact the term "religion" is a pegorative. It's a vision of the spiritiual potential of Britain, and of the fallen human soul. In Blake's worldview, "jerusalem", the spiritual potential of mankind, was indeed "builded here, smong these dark satanic mills". being pedantic, I know, but it bugs me when that's referred to as Blake's Jerusalem. Jerusalem is a poem by Blake, and it s 100+ page epic.