"I AM not sure that we need all this First World War stuff dragged out over four years," someone said to me the other day. After all, he concluded, it is hardly something to celebrate. Commemoration, of course, is a very different thing from celebration. Still, he would have a point if what happens between now and 2018 proves to be only an undifferentiated series of lamentations about the futility of the war to end all wars.

It is easy to fall into a clichéd view of the Great War as a sterile stalemate of fatal, fruitless to-and-fro across the deadly mud between the trenches of the Western Front. Even those who acknowledge the war to have been a massive historic turning-point in British social, economic, and political realities often probe no further into the reality of the war than a dulce et decorum hindsight.

The ceremony last week in Westminster Abbey to mark the centenary of the outbreak of the war avoided that pitfall (News, 8 August). The historian Sir Hew Strachan began by quoting from Sir Edward Grey's reported remark as Foreign Secretary in 1914: "The lamps are going out all over Europe; we shall not see them lit again in our lifetime." It set a sombre tone for the symbolic extinguishing of candles as the service progressed.

But Sir Hew also reminded us that those who went to war in 1914 did not know what they faced. The first reading was from the letter of one soldier to his wife. It recorded the excitement of the men as they went to war. "It's a funny game!" wrote Captain Alfred "Mickey" Chater of the Gordon Highlanders. "We are all fairly shouting with joy at going and I daresay we shall soon be cursing the day and then when we get back we shall say we had the time of our lives!"

War was for those men a grim quest of discovery. That was brought home to me the other day on a visit to the Imperial War Museum's airbase at Duxford, where a demonstration First World War trench has been created. As you enter the trench, it is 1914; when you leave, it is 1918. On the way, you are guided on a brief journey through the changes that took place in uniforms, helmets, gas masks, and weaponry for both sides over the gruelling years. Gas masks went from urine-soaked rags to charcoal filters. Trenchcoats were invented, shortened, replaced with sheepskins, and then jerkins, whose design continued through to the next war; so did the Lee Enfield rifle, in its various upgrades. All of this is a metaphor for understanding more profound changes.

Those who cannot remember the past are condemned to repeat it, Edmund Burke is often quoted as having said (although more careful study suggests that the quotation is from George Santayana). Remembrance is about more than remembering. It should be, as Sir Hew said, less about judging than understanding. We now have four years to understand the war of 1914-18, and perhaps also to learn something about war in our own time. If we do not emerge in 2018 thinking differently, we shall have failed.

Paul Vallely is Visiting Professor in Public Ethics and Media at the University of Chester.