Some of the ideas expressed earlier by Erigena could be a theme for visionary poetry in the hands of Blake.
It is true that Blake is a mystic, but it is not so easy to see him as an anarchist as the title of the Peter Marshall's book states. Behind the speculative arguments in this poem we find some dosage of anarchy. From the very beginning in The Argument, we get the feeling of reading a visionary mystic but at the same time a visionary anarchist. Let's see:
Blake makes a random connection between knowledge and experience. There is a subtle anarchy in the way he relates knowledge and experience. His verses are concise and clear. They go right to make a point, but at the same time we sense some kind of rhetorical speculation right beneath their roots. This is poetry. It is not really philosophy. Blake knows this fact about his poetic discourse, so he is free to speculate, to sing freely asserting that "all religions are one" without giving sound theological reasons for this bold assertion. Blake continues in the same vein with his seven principles. The first one equals Man to an angel, a spirit and a demon in a verse characterized by its tight syntax and its semantic freedom. Let's see:
The Poetic Genius is an equality essence that gives unity to Blake's vision, to Blake's verse. The unitary element in Man's diversity is the Poetic Genius according to Blake. ...