When would to describe the scope of this changing? Milton himself wrote literary essays on cultural topics of his times (areopagitica in 1644 was a pamphlet pro

When would to describe the scope of this changing? Milton himself wrote literary essays on cultural topics of his times (areopagitica in 1644 was a pamphlet protesting the banning of unlicensed works, which was already a fairly debated and settled topic within the literary sphere by the time he published it). Death Of the Author itself was written in 1967, which debates the merit of analyzing literature on the authors intent and not what is literally on the page regardless of the authors intent. At what point we things not cultural discussion?