Surprised by Sin: The Reader in Paradise Lost
http://www.hup.harvard.edu/catalog.php?isbn=9780674857476&content=reviews
This book by great lit-crit Stanley Fish makes the point that Milton -- against his own conscious intentions -- writes the character of Satan as the true hero of Paradise Lost. That as he rebels against the Almighty, the Father and Son come off as pompous, arrogant, overbearing, whereas Satan is the questor in search of authentic, autonomous being.
That Milton is not, in heart & mind, the Puritan that his essays self-portray. But rather the forerunner, really, of the Romantic poets.