It takes its title in part from Areopagitikós (Greek: Ἀρεοπαγιτικός), a speech written by Athenian orator Isocrates in the 4th century BC.

Some argue that it is more importantly also a reference to the defence that St Paul made before the Areopagus in Athens against charges of promulgating foreign gods and strange teachings, as recorded in Acts 17:18–34.

"[4] This issue was personal for Milton, as he had suffered censorship himself in his efforts to publish several tracts defending divorce (a radical stance which met with no favour from the censors).

In particular, The Doctrine and Discipline of Divorce (1643), which he published anonymously and unlicensed, was condemned by the Puritan clergy as being heretical and intending to foster sexual libertinism, and it was cited in petitions to parliament as evidence of the need to reinstall a system of prepublication licensing.

[6] According to George H. Sabine, the Areopagitica presumed and was written for an engaged public: Its basic principle was the right and also the duty of every intelligent man as a rational being, to know the grounds and take responsibility for his beliefs and actions.

Its corollary was a society and a state in which decisions are reached by open discussion, in which the sources of information are not contaminated by authority in the interest of party, and in which political unity is secured not by force but by a consensus that respects variety of opinion.

Milton defends this purpose, holding that to bring forth complaints before the Parliament is a matter of civil liberty and loyalty, because constructive criticism is better than false flattery.

[8] He concludes his introduction by encouraging Parliament to obey "the voice of reason" and to be "willing to repeal any Act" for the sake of truth and upright judgment.

Milton provides historical examples of the aftermath following the Inquisition, including how there were popes in Rome beginning in the 14th century who became tyrannical licensers.

Milton points out that encountering falsehood can actually lead to virtuous action, such as how St. Paul's converts had privately and voluntarily burned Ephesian books considered to be "magick".

Milton objects, arguing that the licensing order is too sweeping, because even the Bible itself had been historically limited to readers for containing offensive descriptions of blasphemy and wicked men.

This is because many authors will produce a written work with genuinely good intentions only to have it censored by what amounts to a subjective, arbitrary judgment of the licenser.

Milton seeks a means by which to ensure that authors and publishers remain culpable for any "mischievous" or "libellous" work that they produce.

Milton's ideas were ahead of his time in the sense that he anticipated the arguments of later advocates of freedom of the press by relating the concept of free will and choice to individual expression and right.

Most notably, the Court cited Areopagitica in the landmark case New York Times Co. v. Sullivan to explain the inherent value of false statements.

[16] Later, Justice Douglas concurred in Eisenstadt v. Baird, citing the pamphlet to support striking down restrictions on lecturing about birth control.