We have now seen Milton engaged in teaching and writing on education,
involved in domestic unhappiness, and speculating on the obligations
of marriage. But neither of these topics formed the principal
occupation of his mind during these years. He had renounced a
cherished scheme of travel because his countrymen were engaged at home
in contending for their liberties, and it could not but be that the
gradually intensified stages of that struggle engrossed his interest,
and claimed his participation.

So imperative did he regard this claim that he allowed it to override
the purposed dedication of his life to poetry. Not indeed for ever and
aye, but for a time. As he had renounced Greece, the Aegean Isles,
Thebes, and the East for the fight for freedom, so now to the same
cause he postponed the composition of his epic of Arthurian romance,
or whatever his mind "in the spacious circuits of her musing proposed
to herself of highest hope and hardest attempting." No doubt at first,
in thus deferring the work of his life, he thought the delay would be
for a brief space. He did not foresee that having once taken an oar,
he would be chained to it for more than twenty years, and that he
would finally owe his release to the ruin of the cause he had served.
But for the Restoration and the overthrow of the Puritans, we should
never have had the great Puritan epic.

The period then of his political activity is to be regarded as an
episode in the life of the poet Milton. It is indeed an episode which
fills twenty years, and those the most vigorous years of manhood, from
his thirty-second to his fifty-second year. He himself was conscious
of the sacrifice he was making, and apologises to the public for thus
defrauding them of the better work which he stood pledged to execute.