Caryle probably got it about right when he wrote that "all history is a distillation of rumour". Before any historian reaches for his or her pen, let me add that the comment is not intended as an insult. As journalists we know how difficult it is to be sure of the evidence of our own eyes. Historians, for all their academic training still have to make a personal judgment when it comes to interpreting what happened.
These, somewhat ponderous, thoughts are prompted by the debate that has been going on about the accuracy - and therefore, it is implied, the value - of television dramas reconstructing recent historical events.
We have had Michael Noonan protesting that No Tears, RTE's powerful and beautifully acted series about the Hepatis C scandal, is unfair to him. One of the victims has come to his defence, expressing concern that the series "is not fictional enough to be a drama, nor real enough to be fact".
The same worries have been voiced about the two dramas screened recently on television about the murder of 13 innocent civil rights marchers in Derry ¨30 years ago.
The film Bloody Sunday has drawn criticism - and caused some puzzlement in Derry - because of the prominence given to Ivan Cooper as the main organiser of the march.
I had and still have great respect and affection for Ivan Cooper. He was a brave and important figure in the Civil Rights movement, and not only because his being a Protestant allowed nationalists in Derry to cherish the belief that this was a genuinely non-sectarain campaign for justice.
My own memory is that he was not central to events as they unfolded on Bloody Sunday and that people like Bridget Bond, Bernadette Devlin and others played a greater part.
The makers of the film would argue that using the character of Ivan Cooper - whose warmth and ironic humour were wonderfully caught by James Nesbitt - was a device which allowed a complex story to be told to an audience, most of who would have no knowledge of what happened in Derry 30 years ago.
It was important to get this film screened in Britain on ITV at peak viewing time. Hopefully, it will have helped to persuade reasonable opinion that terrible injustices have been carried out in the name of the British state.
Jimmy McGovern, whose Sunday was shown on Channel 4 earlier this week took a very different approach.
He presented what happened through the eyes and experience of the nationalist community in Derry. This was not history as the lives of great men. Apart from Edward Heath who was shown discussing the problem of how to deal with the fallout from the 13 deaths, there wasn't a politician in sight.
What we were shown was the social and political context of the march. The cramped little houses where several generations of a family lived together, the kind of poverty which meant that one of the characters couldn't afford to have his worn-out shoes mended, a father afraid to be seen carrying his son's coffin because he regarded himself as fortunate to have a job working for the British army.
There were other details that rang true from so many of those early civil right marches; the acrid clouds of CS gas, the humiliation of being forced to run away from the security forces. Above all, we saw the extraordinary physical and moral courage of supposedly ordinary people as they tried to come to terms with what had happened to them as a community. The most telling moment in the whole film comes at the end when we see Leo Young back at his job loading coal into sacks, having rejected the option of seeking revenge through violence.
It has become a commonplace that Bloody Sunday provided recruits and support for the Provisional IRA over the next 25 years. But not every young person who was on the march joined the IRA. Many of them continued to believe, against all the odds, that they could achieve the truth and justice for their loved ones through peaceful and legal means rather than through violence.
That is why it is so important that the Saville Inquiry should be seen to keep faith with the innocent victims and their families. There have been comments that too much emphasis has been placed on finding the truth about Bloody Sunday, while the terrible atrocities suffered by the Unionist community at the hands of the IRA receive very little attention.
The stock answer to this has been that the actions of the Paras were qualitatively different because they were the legal agents of the state, murdering its own people.
This is true but we are reaching a point where the legal response is no longer enough. Both communities suffered appalling losses over the past 30 years. The ongoing row about the inquiry into the Omagh bombing reminds us yet again of people's hunger to know the truth about what happened to their loved ones and why they died.
In the debate that was screened after the screening of Sunday Mark Durkan, among others, recognised that much, much more needs to be done to bring peace to the families of all the victims of the past 30 years.
From time to time there is talk of some kind of Truth and Reconciliation commission but there is little public discussion about it. That is why films like those we have seen recently are so important. They remind us all that peace and reconciliation cannot be separated from the hunger for truth.