Why can it be said that Milton does not represent but dominates his age?
[Milton's] was a more general education than is offered at Cambridge these days, ... equipping him with the tools to write some of the most groundbreaking literature ever seen, and to engage as a polemicist on many different social, political, and theological questions. He remade the moral, political, and cultural world around him; without him, the world we live in would look different. (Gavin Alexander of Christ's College at Cambridge, "Why Milton Matters")
One indicator of why Milton can be said to have dominated his age is the language that we use today that was coined (i.e., originated) by Milton yet sounds modern and contemporary. Milton coined many words still dominant in the English language, and lines from his great works have become adages and truisms that are recognized and used everywhere, although the authorship and origins may be wholly unknown. Some examples of sayings that were originated in Milton's works are:
- The mind can make a heaven of hell, a hell of heaven.
- Fallen on evil days.
- The childhood shows the man.
- The world was all before them.
Some continuously used words of Milton's coinage that sound modern and contemporary include these:
Beyond this, he carried over the rhetorical reshaping of sentence syntax for dramatic or poetic effect and efficiency of expression that Shakespeare made so necessary to the compression of poetry. As a consequence, even today we may use a poetic expression that speaks of the lover spurned who the weeping heart possessed [the spurned lover wept from his heart]. In addition, Milton changed the convention governing sonnets and used them to expose themes as universal as self-doubt, betrayal, and duty.
Milton began trending toward what he considered the best of historic poetic forms. Starting with Lycidas, this trending is evident as Lycidas is written in the form of a Greek pastoral elegy. To do this, he broke with contemporary genres, predominantly metaphysicalist, and began branching out to past great styles of poetry such as pastoral elegies and Greek tragedy, which he used in writing Samson Agonistes. As a result of this break with contemporaneous convention and this reaching out to past great traditions, he became the master of otherwise outmoded forms of poetry.
The result of this is that Milton influenced the breadth and shape of all future English poetry. Had the metaphysicalists of Milton's age continued without challenge from Milton's infusion of Greek, Latin, and Renaissance traditions and conventions, English poetry would have taken a very different, undefined direction. As it was, we had Pope, Keats, and Dryden translating and embracing Latin and Greek and Byron writing in the mock-epic form..This is a summary of the most prominent elements of Milton's work that resulted in his gaining dominance in his age rather than just representing it.
[Answer drawn from the article by Gavin Alexander, Ph.D., Christ's College, Cambridge, "Why Milton Matters," written for Cambridge's 400th Anniversary Celebration for John Milton.]