There is plenty of evidence that the human condition is such that we have a need to believe there is something more than the here-and-now. With the decline in organised religions in the West, there has been something of a shortage in this respect and nature, abhorring as she does a vacuum, has conveniently plugged the gap through the conspiracy theory

Of course, conspiracies do exist. Watergate, for example, and the Matrix Churchill affair in the UK. Clinical paranoia cannot be taken as prima facie evidence that they are not out to get you. But most of the really long-running conspiracy theories are seemingly based on slavish devotion to a fixed idea in the face of overwhelming evidence to the contrary.

The best conspiracy theories involve elements of the urban legend, suspicion of the agencies involved, and always the availability of at least one perfectly satisfactory prosaic explanation. One classic example is Roswell.

The Roswell Incident

The Roswell incident happened in early July 1947 in New Mexico. A craft of some sort crash landed, and the wreckage was bundled away in some secrecy by the staff of Roswell Air Base. Since this base was used for testing experimental aircraft at the time, this was hardly surprising, but then came the rumours that it was a UFO, bolstered by the release of some rather embarrassingly obviously fake film "evidence" of an autopsy on an alien being.

Now, UFO's are a reality. A UFO is defined as: any unidentified flying object. In these days of saturation radar coverage many fewer flying objects are unidentified, but back then it was quite common. Almost all were subsequently identified to everybody's satisfaction, usually being off-track balloons or aircraft. There is nothing which states that a UFO is necessarily of alien origin; in fact, every UFO which has since been satisfactorily identified (i.e. most of them) turns out not to be. But let's not get embroiled in that particular discussion; whether or not sightings in out-of-the-way American one-horse towns are the work of Strags or not is irrelevant here

The crucial point about the Roswell incident is that absolutely everybody involved refuses to admit that it was anything other than a weather balloon, or materials consistent with a weather balloon. This is taken as evidence that there is a conspiracy. Of course this kind of thinking is not unique; it was, after all, precisely this kind of argument which Oolon Colluphid used to extrapolate proof of the non-existence of God based on the existence of the Babel fish. But think for a moment: it would require that every single person involved was prepared to tell an orchestrated and consistent lie, even after they had written authority from the President of the United States to reveal the truth of what happened. Consider for a moment the likelihood of a completely leak-free conspiracy.

And it is this which makes the Roswell incident the perfect conspiracy theory: the existence of absolutely no evidence whatsoever to support the alien spaceship theory is taken as proof that not only was there an alien spaceship, but that a huge and wide-ranging conspiracy exists to cover up this fact from the American people.

The Tunguska Incident

Like Roswell, the Tunguska Incident is a perfect example of how people will refuse to accept a prosaic explanation for an extraordinary event. At approximately 7am on June 30, 1908, there was a large explosion in Siberia, near the Lower Tunguska River. Considerable damage was done, and the blast was undoubtedly felt several hundred miles away.

At the time, there was no convincing theory as to what happened, but there were several odd features of the site, including the fact that trees directly under the epicentre of the explosion were still standing, while those some distance away had been flattened outwards. The conspiracy theory is based on the fact that the same singular features were observed in the Hiroshima and Nagasaki nuclear bomb blasts.

Now, it is obvious to even the most casual observer that any air-burst explosion would cause this effect; the trees at the epicentre experience blast directly downwards, so will of course not be blown over. No matter. Despite the lack of debris of any kind, the fact that there is no measurable increase in background radiation, and the fact that the nuclear weapon was not invented until some 30 years later, a nuclear device it must be, say the theorists. The possibility of a re-entrant comet, or a meteorite whose temperature caused it to explode, cannot be considered. And having decided on a nuclear explosion, it must of course be of alien origin.

So in are trotted the usual arguments. People who spotted "saucer-shaped objects flying through the sky" (why are these only ever observed by lone eccentrics, one wonders?). Speculation as to why the KGB made no statements about it (the fact that they weren't founded until forty-odd years after the event is apparently no excuse). And so on.

JFK

Here at least is one conspiracy theory which is probably based on an actual conspiracy. There is little doubt that JFK made powerful enemies, and his conduct was such that his powerful friends were in equal danger from his presidency. The problem, for the theorists, is which conspiracy theory to believe. Was it the Mafia? The KGB? The CIA? The FBI? An embarrassment of riches. The conspiracy appears to be that there are so many conspiracy theories as to make it impossible to pin any one of them down. Or perhaps, like the Murder on the Orient Express, they all did it.

Diana, Princess of Wales

Diana, Princess of Wales, died in a car driven at lunatic speed by a drunk Frenchman. The only survivor of the crash, which also killed her companion Dodi Fayed, was also the only person in the vehicle wearing a seat-belt.

But this was not good enough. The British nation wanted someone to blame, because (as in America) all tragedies must be somebody's fault. First, they blamed the paparazzi. Which worked well enough until someone noticed that they weren't close by at the time. Then there was the small white car. Anyone, in fact, except the driver, Henri Paul, an employee of Dodi's father Mohammed Al Fayed - a.k.a. the Phoney Pharaoh - owner of Harrods but not, alas, a British passport.

The rich and beautiful must not die in such mundane circumstances! But after a while it was found that it was precisely that mundane, and the furore started to die down. Except for Mohammed Fayed, purveyor of brown envelopes to the British Parliament. Oh no, he insists that there was a conspiracy involving Prince Philip (Diana's father-in-law), the security services in the guise of MI5, Mossad, the French police, and just about everybody else he could think of. How could it possibly, after all, be his fault for letting a drunk idiot drive his son in a car at breakneck speed through Paris?

So this is an example of another form of conspiracy theory; one which is very much like a paranoid delusion, and which is intended to cover the feelings of guilt and inadequacy one might feel over something of which one is less than proud.

The National Enquirer

One key reason that conspiracy theories survive is that they are nurtured. These days the Internet is such that even the most bizarre opinion is likely to find a following somewhere (if you don't believe this, read up on Mike Corley). And one of the key nurturers is the [broken link] National Enquirer, a magazine which combines the unbelievable with the merely unpalatable. This is the natural lavatory reading matter for those who sincerely believe that Elvis was abducted by aliens, this being more comforting than the traditional explanation that he simply took too many drugs.

The National Enquirer has its imitators, such as the UK's Sunday Sport, with its "exclusive" story about a second world war bomber being found on the moon, but has no real equals.

Survivalists

No consideration of conspiracies would be complete without mention of the survivalist cults of North America. These are people who stockpile arms and food against the day when the American Government will turn against the people. Or there will be a nuclear war. Or the entire planet will be eaten by an enormous mutant star goat, or some such.

However jaundiced your view of early 21st Century American government, and to be fair that can be pretty jaundiced without straying from the mainstream - given that candidates are happy to spend tens of millions of dollars to be elected President, there must be some kind of payback - it is scarcely credible that the future of the world's largest economy could be in the hands of the readership of Soldier of Fortune magazine.

Conclusions

Strange and remarkable things do happen, of course, as do conspiracies. But in a world where nature can give us Krakatoa, St Elmo's Fire and the Coelacanth, we seem to have a perverse need to look for bizarre explanations when none are required. There can be no other explanation for the observed fact that some people believe that the X files is a documentary.