One of the most numerous arguments that I have heard against conspiracy theories is that it would not be possible for a large group of people to keep such a secret.
However I think that I can put a good argument in response to this view and give people some ammunition against these naysayers.
To address the issue of keeping secrets, you have to start with yourself. Do you keep secrets? I would argue that yes you do, and everyone does without too much effort, What is more; you are able to keep secrets for years without anyone finding out, or being any the wiser. Secrets about sexual affairs, or private bank accounts, secrets about where you go once a week, or why you stay late at work, almost every area of life has secrets, it's part of being human that we keep secrets. It is even possible for people to keep secrets from themselves and have their brains believe it; secret eaters pretending that they are sticking to a diet plan, or secret drinkers who swear they are tee total and drink behind their partners back, but manage to convince themselves so absolutely that they don't do it, and that no-one knows or will find out. We are a very secretive bunch!
The next stage from this brings me back to the sexual affair between two people, some of these affairs are found out eventually, but I bet most are not, and its only those people who are able to keep a secret who are the ones that can have affairs for years on end without being found out by their nearest and dearest. It can be seen then that two people can keep secrets and do in our society, and now we are beginning to break the argument of secrets.
Moving onto groups of individuals (2-100s), well a sad sign of the times is that seemingly well adjusted people can harbor such hatred of a system such as religion or government, that they band together to create a secret terrorist plan to attack the system. Now millions of pounds every year are spent on counter terrorism, and on finding these groups of terrorists before they attack. We know that they do attack without our knowledge of their secret plans, and when they do it catches us all out. So why then, if we can't keep secrets, are anti-terrorism police needed at all? Why bother try to crack these secret plans if someone is always going to spill the beans? The answer is that the terrorists won't crack and don't more often than not, because we humans can keep group secrets.
The next step is large groups (100s - 1000s), and a good example of this is the Freemasons. This is a large ancient group of people which are known to keep secrets, we don't know what the secrets are, and millions of people are always trying to infiltrate or bust open Masonic secrets, I've had a go myself! and despite a few claiming to have been in the order and then kicked out for telling all to the media, the secrets are still secret! How can this be if secrets are not able to be kept by large groups? Secret societies are numerous in our world and it is a recognised part of our civilisation. Now I can show that the secret dogma is crumbling as an argument, but not just for non-profit groups, in the business world too, companies use their company law to prevent employees from speaking the truth, and this seems to be on the whole a very effective way of keeping a secret. I've been through it and i'm sure you will have also, especially when it comes to company quarterly numbers, and redundancy notices, we are all told that talking to the press is deemed as gross misconduct, and we will be sacked if we tell. Companies will only employee staff that are compliant with their rules, and screen people during the interview process, and those who are noticed as rebels and whistle blowers will not be employed. Organisations go about arranging for their secrets to be kept, and there's no luck in it, it is planned from the beginning. The most extreme example of a company that recruits in this way would be a defence company that requires its employees sign the Official Secrets Act, did you get that, the "Official" Secrets Act! Now if people can't keep secrets, what is this policy document for? There are of course different levels of secret in the act, and only a few will have the higher levels such as MI5/6/SOCA and the other security and intelligence services, but look; secrets are now governmental policy!
So Finally comes some speculation, but on the back of the evidence of our own witness I have to ask the question;
Is it possible that governments and their agencies, along with the military at their side, are all able to keep big secrets from us?
It absolutely has to be the case!
It is more than probable that governments always have secret plans for the future, and have always covered up secret actions that they have taken in the past, and they are secure in the knowledge that their secret is safe. Remember that government organisations don't employee the average joe, employees are hand picked and screened from the millions of people out there, and for secret work, the individual is not enough, as people's backgrounds, friends, and family are also screened. The employees with the knowledge are those least likely to spread it, they can keep secrets.
So individually, in pairs, in groups, and in organisations, secrets can and do exist. There is no doubt in my mind about this and while given enough time, these secrets tend to be eventually leaked or found out externally, it is either too late to be relevant or so far removed from peoples day-to-day that people don't care anymore. Take the Iraq war and the question of WMDs, who cares now? Its old news! Tony who?
The only remaining question now for me is why would people want to put out the idea that it is impossible to keep a secret?
Well at an individual level, I can see fear playing a big role in the idea that secrets can't be kept. If an individual with a secret makes everyone around them believe that secrets can't be kept, then they can't possibly have a secret in the eyes of those around them. It serves their purpose to have people believe that it's not possible for them to keep secrets, as this will paint an honest and open picture of themselves and thus cover up the truth. It will also lessen their fear of being found out by enquiring minds.
Well if you ramp this idea up through the ranks of pairs of people, small and large groups, and organisations and governments, then that fear never changes, and always works in the same manner, i.e. the more we talk about it not being possible to keep secrets, the more we will appear to not keep them, and the less fear we will have about being found out.