The _Purple Island_ is man, whose body is anatomically described after the allegory of a city, which is then peopled with all the human faculties personified, each set in motion by itself.

They say the anatomy is correct: the metaphysics are certainly good.

The action of the poem is just another form of the _Holy War_ of John Bunyan--all the good and bad powers fighting for the possession of the Purple Island.

What renders the conception yet more amazing is the fact that the whole ponderous mass of anatomy and metaphysics, nearly as long as the _Paradise Lost_, is put as a song, in a succession of twelve cantos, in the mouth of a shepherd, who begins a canto every morning to the shepherds and shepherdesses of the neighbourhood, and finishes it by folding-time in the evening.

And yet the poem is full of poetry.