We commissioned these films because the question of democracy seemed to us to be the single most important political issue of our time. We and our film-makers have a lot to say about democracy, but don't think of what we present here as a single, linear argument: look for variety and inconsistency, enjoy incompleteness. In a true state of democracy, every man is a philosopher.

Our films begin with questions. Not all of these are answered, and they most often lead to more questions. This is a feature, like it or not, of the practice of democracy.

And think of the beginning of this century. Democracy appears to hold sway - outside China and North Korea, more than lip service is paid to the way in which people must be allowed to choose their governments, and govern themselves. Wars are fought, and democracy is established afterwards. Problems as diverse as the heating of the planet and the avoidance of famine are presented as having to do with individual rights - we assume that democracy will get us out of any jam. Faintly, the concept of global citizenship exists - reflected in a renewed interest (among the young, most of all) in the international rule of law, the idea that the planet is ours to ruin or save, and that what happens depends on the wishes and actions of all of us. In that sense the world of our new century, however, imperfectly, can be said to be 'democratic'.

But it's more complicated, isn't it? We applaud the arrival of democracy in places where it didn't exist. Yes, it's good to see a real, elected government after so many years of civil war, as is recorded in our film from Liberia featuring our heroines led by Ms Johnson Sirleaf. It would be foolish not to acknowledge so many victories, often against the odds. But we can reflect, too, on places where the 'transition' has been difficult, or where, perhaps, it hasn't happened at all. The burden of our film from Egypt is this: good people struggle for democracy, but the outcome is uncertain.

We want to start a conversation. We've approached people to make films about places from which they come, or from which they have escaped. Brilliant, mostly young film-makers - people with a sharp eye, able to spot whatever is unusual in our troubled, strangely optimistic age. But, of course, Why Democracy? is more than these ten films, it's also a media event. We work as broadcasters, and want to reach as many people as possible.

No one has ever organised the simultaneous transmission of factual television in so many countries, nor reached the hundreds of millions of viewers that we will. Then, for people to join in, there's the web - where our unique website, run democratically by young people from across the world, will host a debate that spans the globe. But above all, there'll be a chance to think about Democracy. Enjoy it.