John Milton's Areopagitica protests against and calls for the repeal of the Licensing Order of 1643, which required all books to be reviewed by the official censor before being published. Milton begins his argument by praising Parliament's history of defending liberty. He then explains that a free press was a highly valued aspect of ancient Greek and Roman societies. Milton also provides examples of tyranny through censorship, such as those seen in the Roman Catholic Church. As a Puritan, Milton is critical of the Catholic church. He warns that Parliament could be toeing the line of the tyrannical censorship of Roman Catholicism or the Spanish Inquisition. 

Milton also argues that the destruction of literature deemed inappropriate or unacceptable does not benefit society, as it offsets the balance of good and evil and hinders a person's pursuit of the truth. Milton believed that a person's reasoning skills would guide them, and if the Parliament was truly Christian, it would see the value in letting citizens experience these trials of morality. To support this claim of good and evil, he references the story of Adam and Eve. Through this reference, he explains that God did not intend humanity to live in a world absent of evil. Instead, by creating the apple in the first place, God allowed choice. If Parliament removes these trials of morality, then people are deprived of making their own choices. From Milton’s Christian perspective, it is better to be well-informed and fervent about one’s beliefs rather than blindly following what one is told is acceptable. Someone could be a heretic who “believe[s] things only because his pastor says so.” With no alternatives to one’s opinions, censorship creates followers with no real stake in their belief system. Censorship, therefore, would be a detriment to Milton and his fellow citizens. 

Milton takes issue with putting truth in bounds, or defining it sharply. Truth, he says, has been “scattered” into the winds and life itself is about the pursuit of this knowledge. It is unlikely that humanity can collect all of these pieces of truth—this is something that Milton believes can only happen with the second coming of Christ. He opposes Parliament’s attempts to suggest that truth is found with censorship. Truth can take many shapes and forms; it is not within Parliament’s ability to harshly define how these must look.

Finally, Milton claims that humans will always experience temptations and that no amount of outside meddling would change that. The number of censors that would be needed to completely rid the world of these temptations would be astronomical and against the country's best interests. These temptations or instances of evil could include excess food consumption in one’s own home (gluttony), dancing or movement, singing, or the spreading of gossip. Milton points these activities out to suggest how baseless literature censorship would be unless Parliament intended to control nearly every aspect of living. All of life “may be fitly called our book,” thereby making it impossible to eliminate evil at the hand of Parliament as a governing body.