Milton's style is thorough, and rooted in an impressive mastery of classical history and literature as well as Scripture and the writings of the early church fathers. In fact, much of Areopagitica is a history of censorship itself. He shows through a string of examples that prior restraint, which Parliament sought to implement through licensing, had long been held to be inconsistent with the development of virtue and intellect. Indeed, one of the crucial connections Milton makes would have resonated with Protestant Englishmen: censorship, he claims, was a practice of the Catholic Church, as the Council of Trent had demonstrated.
But for all its erudition, Areopagitica is above all noteworthy for the passion with which its author defended the free exchange of printed material. His famous observation that it was "as good kill a man as kill a good booke" has been cited by lovers of learning ever since, and his earnest request that Parliament simply "Give me the liberty to know, to utter, and to argue freely, according to conscience, above all liberties" is a fundamental precept of modern civil libertarian thought.