Milton - Areopagitica

Milton's big essay on freedom of speech and why it's a good thing.

Basically, the point here is that he's trying to get Parliament to get rid of a proclamation allowing mass censorship of books. He in essence points out why all this is a bad idea, aside from showing that it's logistically impossible to ban all the bad books.
First of all, books are creations of humans and thus are, in essence, a reflection of the human who created them - meaning that books are in a sense reflections of God (since humans were created in God's image) - and one wouldn't want to censor God. Furthermore, by burning a book, one is burning an immortal imprint of a soul...
Second, good readers can get good things out of bad books as well as out of good books. Good readers are judicial enough to understand what is beneficial v. what isn't, and good readers need to have access to the bad as well as to the good as it is that access to bad/evil which allows them to understand what is good - good/evil are mutually exclusive, mutually defining terms - you can't have one without the other, just as you can't know good without evil and that it is understanding of evil that allows humans to understand good after the Fall. Having access to both good and bad books allows for good judgment.
Third, bad readers can get bad knowledge out of good books through misinterpretation. People may try to censor so that badness does not spread among people, but this is impossible in practice -- things could be printed in other languages and transmitted that way, etc., Finally, and most importantly, there is no real way to set up anyone as a censor, because putting someone in the role of censor implies that this person is somehow far beyond the common amount of knowledge and would thus be able to discern what is good and bad for people to read. This would seem to be fetishizing the knowledge of one person in particular.
Next, not even the Inquisition in all of its power and fury was able to come up with a way to effectively ban books and censor peoples' reading of them.
To censor books would be to take away free will from people. People were given access to reason by God so that they might use that faculty, rather than allow it to rot - this means that people should have unfettered access to books in order to exercise their judgment and their virtue, etc. Finally, even in ridding the world of all the sinful books would not mean that people would suddenly cease to sin - the sin remains internal even if the outside enablers disappear.

England, he says, is often (if wrongly) held up by learned men in other nations as being a place of unfettered knowledge and debate - he doesn't want England to lose its reputation for being so open minded, and does not want the country to fall under the tyranny of censorship, which he repeatedly aligns with the Spanish Inquisition. Finally, he considers it to be insulting to the English people that they couldn't hypothetically be trusted with pamphlets and whatnot, because they should be trusted in the free exercise of their good judgement. This then allows for a the creation of new opinions and free debate, which then leads people to a better understanding of Truth - and by understanding Truth, we better understand the Will of God.

Furthermore, (though this is more me than Milton and what I'm pulling out of Milton in general) the idea of banning books means that people are, in a sense, idolizing the books, because it would be granting to the books themselves a level of power over humans, and a sense wherein books are the sole repository of Truth, rather than allowing humans to interpret books as according to the divine spark of God within them. This strikes me as being particularly Lollard-like in tendency. Enlightened people should be allowed the free and open debate of all topics.