A rule for narrating history as poetry

"The poetry of history," wrote British historian George Macaulay Trevelyan, "lies in the quasi-miraculous fact that once, on this familiar spot of ground, walked other men and women, as actual as we are today, thinking their own thoughts, swayed by their own passion, but now all gone, one generation vanishing after another...." That's why I love history – for its transience.

There's a belief in some circles that history is a branch of science, that there is some sort of objective truth out there that can be parceled out, inventoried – and, most important, assessed by the ultimate guardian of truth, the school exam.

Nonsense. History is poetry, as Mr. Trevelyan said – illusion, imagination, a whiff of what might have been as elusive as wood smoke on an October evening. Its delight lies in its fragility. You can sense it by visiting a place, by touching an ancient document. Or you can convey a sense of history by telling a good story.

The words "history" and "story" come from the same root. In many languages, they are the very same word: When the French or the Italians read their nation's history, they are reading, by definition, the story of their country. It is our English-speaking fallacy to glorify history as something more academic and pompous – and to risk missing out on the simplest and most pleasurable way of bringing the past to life.

I love stories. I tell them for a living. Every journalist contributing to this newspaper is telling you a story – based, of course, on the facts as accurately as he or she can ascertain them. But the facts are spun into a sugar basket of narrative that adds sense and meaning and, yes, a good dollop of entertainment. It is through stories that we can bring people and events from the past to life. That's why we should value narrative more highly.

Our minds are geared for narrative, working out what happened first and what happened second. It is how we make sense of the world. Ask someone to tell you about themselves and they will tell you their "story." How do the great religions of the world enshrine themselves? Through inspiring narratives set down in books.

Sorting out what came first and what came next is the basis of history, the tough, unbending essence that formulates the rule: One thing leads to another. When I am writing a biography, I sort the events of my subject's life onto sheets of paper, dated chronologically in a loose-leaf folder. As I seek to explain the event on the sheet in front of me, I shuffle through the previous sheets – going backward to examine the events up to this date. In many cases, the sequence of happenings set out on those sheets provides me with an inexorable explanation of how things came to be.

But I do not allow myself to turn over the page. I am not allowed to peek forward into a future that did not, at that particular moment, exist. One thing leads to another – it is the narrative imperative, and though it may sound obvious, it is a principle that needs proclaiming and defending in the age of the mass media conspiracy theory.

The conspiracy theory is the direct opposite of history. It doesn't explain an event by going back into its origins. It leaps forward into the future and plays with hindsight, asking the question, "Who came out on top?" Conspiracy theorists propose, say, that the British royal family benefited greatly from the death of Diana – a disputable prognosis, but let it pass. This leads to the enticing but quite unsubstantiated assumption that if the palace benefited, it must also have caused the accident, from which point they are free to ignore reality (even princesses die in car crashes) and concentrate on mysteries: the Fiat Panda, the blinding flash of light, mixed blood samples – surely there's a grassy knoll in there somewhere?

The problem with conspiracy theories is the culture of helplessness and victimhood they engender: Life ruled by conspiracies is a fearful and paranoid experience, a succession of magic events manipulated by sinister forces beyond our control.

Real history, on the other hand, encourages understanding and rational action. At the risk of sounding grandiose, I would claim that it fortifies mental and social health. It teaches us the true cause of things, and what influences human beings to act in the noble and cruel ways that they do.

After a lifetime studying the past, I have come to believe that, in the long run, no- bility actually secures more effective outcomes than cruelty, ideas matter, change is possible, knowledge dispels fear – and good, narrative history both explains and facilitates all those things.

• Robert Lacey is the author of "Great Tales from English History." The third volume, "The Battle of the Boyne to DNA, 1690-1953," will be published next month.