The English civil war is not just a good setting for a drama. It is the messy birthplace of the modern intellectual world. This period is a sort of ideological Big Bang, to which most of the principal political and religious movements of subsequent centuries can be traced: secular liberalism, socialism, democracy, republicanism, Protestant nonconformity, the American revolution — maybe even 1960s counterculture (see Ranters and Quakers). It should be illegal to teach history students about Nazis, or anything else, until they have some grasp of what happened here.

Revisiting the period is more necessary than ever. The debate about religion and secularism that has raged since 9/11 can best be understood with reference to England in the mid-17th century. America’s culture war has its roots here. This slice of history holds the key to the most profound debates of the Anglo-American world.

The civil war was not between monarchists and republicans — the opponents of Charles I wanted to rein in the monarchy rather than abolish it. But the MPs who stood up to royal power were not motivated by a belief in parliamentary democracy. What galvanised them was religious concern: they feared that Protestantism was under threat from an essentially Catholic regime. Charles had reformed the Church in an Anglo-Catholic direction, giving new powers to bishops.

Does that mean the king was opposed by “Puritans”? Yes, but here we must tread super-carefully. Puritanism is a most misunderstood movement. It is widely assumed all Puritans were moralistic control freaks, a Protestant Taliban. This idea is entrenched thanks to generations of Tory and/or Catholic writers, from Samuel Johnson to Paul Johnson. Actually, the Puritans were split down the middle — between strict Calvinists, who fit the above description, and liberal idealists, who do not. These liberal Puritans insisted that toleration was basic to reformed Christianity. The most radical among them argued there should be no official state religion; they invented the separation of church and state the Americans put into practice in the next century. John Milton was their theorist-in-chief.

At the start of the war, this internal divide within Puritanism was repressed by the necessity of beating the king. Victory, however, brought the huge question of what sort of new order should emerge, and the differences between liberal and conservative Puritans came out. Oliver Cromwell was a liberal: he could barely stomach the Calvinists he fought alongside and was determined to keep them from power. The new order had to be based on the idea of liberty, which meant toleration for various types of Protestant, not a new Calvinist establishment imposing uniformity.

Cromwell’s liberal Protestant vision, however, was criticised not just by the religious right but by the radical left. The Levellers, one of whose leaders features in The Devil’s Whore, tried to kick-start modern democracy, and the Diggers set up socialist communes. Cromwell was semi-sympathetic to such ideals, but warned that anarchy would result from their overhasty pursuit. In a sense, he is a new- Labour figure: the progressive ideal can be realised only if a broad consensus is forged and gradualism preferred to radical action. He was awesomely sure that God wanted England to pursue this pragmatic liberal path — his faith makes Tony Blair look like an agnostic.

Judging from the publicity, it looks as if The Devil’s Whore has a romantic-leftish bias, seeing the Levellers as a progressive force thwarted by Cromwell’s self-serving conservatism. It has become almost obligatory to portray Cromwell as a nasty piece of work. (See the film To Kill a King — in fact, don’t bother.) In reality, the suppression of the Levellers was necessary, like the ditching of clause 4. The story of a doomed socialist movement is a distraction from the main story, Cromwell’s rather heroic attempt to invent the liberal state.

Actually, now is the time to rediscover Cromwell’s vision. He wanted a new sort of political culture, in which no strong religious institution was allowed unaccountable power, and saw that the Calvinists were as dangerous as the Anglo-Catholics. Despite his intense faith, he was one of the first “secular” figures. The true meaning of secular is not “anti-religious”, but “opposed to authoritarian religious institutions”. This is overlooked in the contemporary debate about the place of religion in society. We need to rediscover the liberal Puritan insight that there is no necessary opposition between religious faith and secular freedom. This is the big idea England produced in the 17th century, but lost sight of. We let America take it over, with mixed results.

Should this drama highlight the relevance today of this turbulent period, it will be genuine public-service broadcasting.

Milton’s Vision: The Birth of Christian Liberty by Theo Hobson is published by Continuum

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