If you want to believe there has been a conspiracy, your belief will be very hard to dislodge. The lesson of the report into the death of Diana, Princess of Wales, confirms that truth.
You can involve one of the most experienced police officers in the land; he can pursue every possible line of enquiry, carry out every kind of forensic test, engage the co-operation of police forces elsewhere, and report finally that there is no evidence of a conspiracy, indeed that the evidence points conclusively in the opposite direction.
You can do all these things, and still at the end of the day those who believe that there was a conspiracy to murder demonstrate their tenacity in the face of all that has been unearthed by calling it a cover-up.
The four young people who were tragically killed near Ombersley recently was a stark reminder of the daily toll of people who are killed at the wheel of their cars, and whose families also bear a life-long toll of grief.
But somehow it is harder for people to accept that such a famous person could have died in such an accident.
There are all sorts of agendas running here. We all know how close anger is to grief, how undischarged grief interlocks with undischarged anger.
We are sad. We cannot accept the real cause of our grief, so it must be somebody’s fault.
And the bigger the grief, and the more important the object of our anger – and who greater than the Royal Family? – the more the conspiracy theory sticks.
The reality is, however, that extraordinary people die very ordinary deaths, and people whose lives are marked by style and pomp end their lives in sad and unpleasant circumstances.
What we have to learn to do in the face of that is to grieve and be grateful, not allowing that to turn to anger or the search for someone to blame.
We approach the tenth anniversary of a death that transfixed the nation in grief not searching for a way to attack someone, but rather for a way to honour the memory of a remarkable figure of our time who symbolised the possibility that the most well known of us can reach out to the least of our society in compassion.