What is "areopagitica"

Areopagitica; A speech of Mr. John Milton for the Liberty of Unlicenc’d Printing, to the Parlament of England is a 1644 prose polemical tract by the English poet, scholar, and polemical author John Milton opposing licensing and censorship. Areopagitica is among history's most influential and impassioned philosophical defences of the principle of a right to freedom of speech and expression.

Today, Areopagitica is regarded as one of the most eloquent defences of press freedom ever written – and as one of the most influential, because many of its expressed principles have formed the basis for modern justifications.