It is 100 years since the first bill to introduce conscription in Britain received royal assent. That same bill also introduced the concept of conscientious objection to the law. Thus were two milestones achieved in one law. The conscription bill meant the state claimed the right to force unmarried men to die for their country. But it also renounced the right to force anyone to kill.

As we contemplate the apparently limitless horrors of the first world war, it is worth remembering that some at least of the ideals that the propaganda claimed we were fighting for were real, sincerely held, and in fact advanced in that period. Liberty of conscience was one of them. Militaristic states had recognised religious objections to killing before. The Mennonites, German-speaking precursors of today’s Amish communities, refused military service from their earliest beginnings in the 16th century, and this right was recognised by the Dutch Republic even during its existential struggle with the Spanish empire.

Quakers were specifically exempted from the very earliest precursors of English conscription laws, such as the Militia Ballot Act of 1803, and throughout subsequent discussions. But they were not content with this. What Quaker MPs such as Arnold Rowntree fought for was the recognition that anyone, whatever their religious or atheistic beliefs, might feel a conscientious objection to killing which the state should recognise. This was not a popular position at all. One backwoods peer, the Earl of Malmesbury, chuntered that “I consider that any man who has a conscientious objection to taking up arms for his country is sailing dangerously near the very ugly word ‘traitor’ … The conscientious objector … is nothing more nor less than a man who dislikes discipline of any sort whatsoever.”

The early conscientious objectors, whatever their motives, faced enormous hostility and persecution in their efforts, and if they were conscripted into the support services in the frontline, they faced all the dangers of the armed men alongside them. Their courage was at least as great, possibly greater: an EE Cummings poem about the bullying and murder of “Olaf glad and big … a conscientious object-or” concludes with a memorable expression of respect: “Christ(of His mercy infinite) / i pray to see;and Olaf,too / preponderatingly because / unless statistics lie he was / more brave than me:more blond than you.”

It might seem that this is only of historical interest. Conscription is long past and modern weapons make it hard to imagine that this country will ever fight another war with a conscript army. Such voices as argue for national service do so on the grounds that it would be good for young people, not that it would be bad for possible enemies.

It is tempting to see the progress in this bill as part of a larger movement towards making wars a matter of democratic and voluntary consent, so that today we no longer trust the government to declare war at all, but demand the vote of parliament. Yet this step has been accompanied by a coarsening which would have horrified the parliament of 1914. In the first world war we came to use poison gas against enemy troops, and widespread starvation, through the blockade, against civilian populations. In the second, the terror bombing of civilians was almost universally accepted, and afterwards succeeded by the doctrine of nuclear deterrence, which relies on the threat of unimaginable mass slaughter of innocents. Nonetheless, the conscientious objection clauses in successive conscription acts represent a victory for conscience over the forces of murderous conformism, which is one of the finest and most lasting legacies of the dreadful “war to end wars”.