To educate girls is to reduce poverty. That is the lesson that unites us today.

We come to this lesson well-prepared. Study after study has taught us that there is no tool for development more effective than the education of girls. No other policy is as likely to raise economic productivity, lower infant and maternal mortality, improve nutrition and promote health - including the prevention of HIV/AIDS. No other policy is as powerful in increasing the chances of education for the next generation.

And yet, out of the millions of children in the world who are not in school, the majority are girls.

That is why we must redouble our efforts to translate what we know into reality. That is why two of the Millennium Development Goals agreed by all the world’s countries are focused on education for girls and boys alike. These are not only goals in their own right; how we fare in reaching them will be crucial to our ability to reach all the others.

Education is a human right. Fifty-five years ago, the Universal Declaration of Human Rights established that everyone has the right to education. The fact that millions are still deprived of it - most of them girls - should fill us all with shame.

If we are to succeed in our efforts to build a more healthy, peaceful and equitable world, the classrooms of the world have to be full of girls as well as boys. Every year of schooling completed by them will be a step towards eradicating poverty and disease.

Let this be not only the world’s biggest ever lesson, but a lesson that the world will never forget.