And that leads me to what is - I believe - a very important point. There is no doubt that the public wants the NHS. But that desire alone will not secure the future of the NHS. People, not taxes, run our health service. Many of you here, I know, are working incredibly long hours, doing difficult, demanding jobs, in uncomfortable situations. Many of you are carrying out critical tasks for a fraction of what you could earn if you were to take jobs outside the NHS.

I am delighted to be able to welcome you to the second annual King's Fund President's Lecture. Last year this Lecture addressed the role of complementary medicine in modern healthcare practice. This year the NHS has been celebrating its 50th year with many local and national events. As I seem to have been doing something rather similar recently it might be appropriate for someone born in 1948 to take the opportunity of this year's Lecture to look at the achievements of the health service, and at some of the challenges it may face as it begins its next 50 years.

To help this task this evening, we are very fortunate to have one of the world's foremost biomedical scientists, Sir David Weatherall, who also happens to be the Regius Professor of Medicine at the University of Oxford. Sir David is going to use his experience as a medical practitioner, a researcher, and a teacher, to look at the myths and realities of the health service now and in the future. And after Sir David has spoken, we have invited three healthcare professionals, at different stages in their NHS careers, to respond, before, finally, you get to have your say on the NHS.

Before I hand over to Sir David, I hope you won't mind me taking a few moments to share with you some of my particular thoughts on the NHS at 50.

There is no doubt that the NHS is a hugely valued institution. What Nye Bevan, its founder, called 'the greatest social experiment the world has ever seen', has grown into one of the world's largest and most famous public institutions. Yet back in 1948 it might have been very different indeed. This country had just fought the most expensive war in history, and the task of post-war reconstruction of our cities, our homes, and our economy was formidable to say the least. To some, this great experiment might have been expendable. Yet the NHS was founded: supported by people who had fought for a future where the sick and vulnerable would rightly be the concern of us all.

Now this was not a new idea, indeed my great great grandfather, King Edward VII, who believed that the burden of caring for the sick should be spread widely, had founded the King's Fund on this principle, 50 years earlier. Everyone was asked to contribute, voluntarily, according to his or her ability. What was new about the NHS was that its creators did something that many had feared was impossible: they successfully linked the concept of service to state funding. That was indeed a great experiment.

Now, ladies and gentlemen, would we do the same again today? Indeed, could we do the same again today? Perhaps, in 1948, it was easier. After all, millions had already done their duty by serving their country. In 1948 the idea of service in the name of the greater public good was inextricably linked to the world our parents and grandparents had twice fought for. What can we say about that sense of service and duty 50 years on? One thing that we can be certain of is that the NHS will not live to see its 75th birthday if we lose sight of the fact that those concepts must always remain the foundation on which the NHS is built.

And that leads me to what is - I believe - a very important point. There is no doubt that the public wants the NHS. But that desire alone will not secure the future of the NHS. People, not taxes, run our health service. Many of you here, I know, are working incredibly long hours, doing difficult, demanding jobs, in uncomfortable situations. Many of you are carrying out critical tasks for a fraction of what you could earn if you were to take jobs outside the NHS.

So why do health service staff do it? Why do you do it? Well, for you, and for a great many others I suspect, it is because you choose to. Because you actually believe in what you are doing you have a commitment to the public service values of the health service.

But we have to recognise that the role of those in public service 50 years after the foundation of the NHS is very different. From how it was then, many people who use the public service facilities of the NHS now seem to be more demanding, less trusting. They question, challenge, and they blame. Perhaps people would realise how fortunate they really are if they could see the healthcare situation I saw in Central Europe some ten days ago - or for instance could see the state of medical services in Russia. But all this must make it much more difficult to work in the public service than at any time in the past.

So how can we persuade a new generation of young people that public service is a rewarding career? The only answer is that we have to discuss this with our children, teach them about it, be proud of it. And we also have to reward vocation when it is chosen and not disadvantage it. We have rightly celebrated the NHS's birthday this year, and it is a pleasure to see so many who work in the health service here tonight. Yet saying we believe in the NHS in its 50th year may not be enough. Do we not also need to renew that sense of duty, vocation and service which was there at the start - and which must remain there if the NHS is to continue being a success as it sets out on its next 50 years?"