In Areopagitica, John Milton delivers a finely-honed argument in opposition to the Licensing Order of 1643, which restored strict censorship laws to England. Milton relies primarily on classical references; indeed, the title is an allusion to the Areopagus, a hill in Athens and the name of a council who sat in judgement on that hill. In a single word, Milton links the crux of his argument to the zeitgeist of Hellenic antiquity, which held a great fascination for learned individuals of the seventeenth century.
Milton's main argument concerns the fact that other societies, particularly Greece and Rome, did not employ censorship laws yet flourished nonetheless. In fact, Milton maintains that censorship represses society by stifling innovation and discourse and debate. He goes on to demonstrate that even if one could find incorruptible, pure jurors to study potential works for publication, it would still be a very daunting and unfeasible task.
In addition to his classical references, Milton draws heavily on supporting evidence in the Bible. This method of attack also underscores an important difference between Milton's perspective on "free speech" and what we con temporarily associate with "free speech." Milton's primary concern is the search for knowledge; he's interested in the Truth as an expression of divine purity. As a result, Milton isn't opposed to censorship outright--he remarks, for instance, that books may be burned after publication should they be deemed unfit for public consumption. Rather, Milton merely advocates against pre-judging a work before the public has a chance to judge.
Almost four hundred years old now, Areopagitica is nonetheless still a very relevant document today. Its name, and Milton's very academic tone, may deter some people from trying to read it. However, it's pertinent to several issues in modern culture--freedom of speech is one, as noted above, and it also pertains to the ongoing debate over the role of copyright in digital media. While copyright and censorship are distinct devices, both share in common the need to have control over a work; both, as Milton points out with regards to the latter, have the potential to harm a society even as they supposedly work to protect it. By understanding historical attitudes toward censorship, I have a better respect for the nuances of the issues we face today.
As an argument, Areopagitica is intriguing and valuable. As a composition, it's masterful. Milton employs a very stable structure with a clear introduction, in which he outlines the shape of his argument. In addition to his use of allusion, he goes out of his way to compliment his audience--i.e., the Parliament of England--always punctuating his arguments with, "And surely esteemed men such as yourselves" and so on. This is not a loud-mouthed soapbox rant but a very rational work of art, and that's what makes it so powerful.
Although I enjoyed almost all of Areopagitica, there is one part where I must disagree with Mr. Milton--that is, I would argue that one of his points is flawed. As he approaches the end of his speech, Milton opines for freedom of religion--save popery and superstition, obviously, or any such practices as may be deemed harmful to society--those religions should be "extirpated". He never gives any indication of who may determine what types of religious practice society may tolerate. Since Catholicism is only recently overthrown in England (a few decades is brief compared to its long reign before Henry VIII's intercession), England is no stranger to religious upheaval. It's almost a betrayal of one of Milton's earlier points, where he argues that even the best-intentioned of men may not be able to adequately judge the suitability of a work for print--here he seems content in young Protestantism's ability to judge if a religion is acceptable or not.
It's very interesting reading rational works by religious authors from previous ages, now that we're in an increasingly secular era. Biblical allusions can be a powerful ally, but religions have also been overused for justification of a myriad of Very Bad Ideas. It's a fine line these authors walk; Milton walks it with great skill.
Areopagitica is an excellent piece of rhetoric--a well-reasoned argument can be a pleasure to read, or to listen to, as the case may be.