The overwhelming pressures of the immediate always threaten to engulf a teacher’s time for reflection. Three weeks into a new school year finding responses to the who, what, when and how questions leaves little time for the why. Yet precisely because teaching requires people to dig deep, not only into their professional capacity, but even into their soul, “why?” is surely the most important question of all.

Our political leaders know how they would answer. The competitiveness of the British economy depends on having a well educated, highly skilled, flexible, inventive work force. They look anxiously to the Pacific Rim, where growth rates are well into double figures and note the startling priority those countries have given to education. John Major is convinced. Tony Blair is convinced. Paddy Ashdown is convinced. On this - perhaps uniquely - all three are right. It is a strong argument for prioritising education.

I suspect for teachers, however, this justification, while important, is not enough. Fortunately, there are further answers as strong, if not stronger. One, surely, is a social argument. As teachers strive to teach young people how to resolve disagreements without resorting to violence, as they instil in them values such as honesty, integrity, and fairness they are undoubtedly making a contribution to the successful development of communities and indeed society as a whole.

That in doing so they find themselves swimming against a tide of often rampant individualism makes their contribution more worthy of respect, not less. Far from being value-free zones, as John Patten once insultingly called them, schools are the only social institutions which can be relied on to promote the nobler attitudes of humanity.

One looks in vain, and with a growing sense of despair, to support for such values in many families, churches and the media. Of course there are many positive examples but the overall picture is bleak. As Eric Hobsbawm once observed, the presence of the odd cactus and an occasional rainstorm does not stop a desert being dry, barren and inhospitable.

Then there is a democratic argument. It has become a platitude to note the ever-quickening pace of change. It is less often pointed out that one consequence of this is that the pace of decision-making has quickened too. Whether in the workplace or in Whitehall there is immense pressure to make fundamentally important decisions to ever more rapid timetables.

The implications of this for democracy are profound. Either decisions will be made by fewer and fewer people - those who happen to be in the right place at the right time - or we set out to educate everyone to a level where they have the information, power of analysis and (crucially) confidence to participate. If we do nothing, the first option will happen by default. The second option demands standards of education which have never yet been achieved anywhere on earth.

Finally, there is an environmental argument best summed up by George Walker, head of the International School, in Geneva in his moving Harry Ree Lecture. “Why,” he asked, “should (students) worry about the 90 million annual increase in the world’s population. . . the 400 million unemployed in the “South”, the annual global per capita expenditure on the UN of $1.90 compared to an arms expenditure of $150, ozone depletion, drought, famine and poverty “There is of course one very obvious reason,” he continued. “Anyone . . . over the age of 50, given reasonably good luck, can expect life to go on much as it is now until we achieve our generous life expectancy. Those of you between 20 and 50 will need unusually good luck for that to happen and anyone under 20 . . . has no chance at all. Something is going to have to change and this creates what a distinguished US ambassador to the UN . . . recently described as ‘the culture of necessity’.”

In other words, humanity depends on the next generation solving global problems which the present generation has either inherited or created and singularly failed to solve. It is for this reason that school improvement cannot be just a passing fad but must become an essential component of creating sustainable global development.

However, the implications of the argument go far beyond even that. Every one of the problems identified by George Walker is an international one. None is amenable to solution by a national government acting alone. Just as Stalin’s heirs discovered that socialism in one country is not possible so we are discovering that exactly the same applies to capitalism. It would be a profound error to tie school improvement too closely to the salvation of the British economy.

It must be much more ambitious. Ultimately, its aim must be the successful education of future citizens of the globe: young people who not only commit themselves to their community but also concern themselves with the well-being of their fellows in Namibia and Nantucket as well as Neasden. Incidentally, Nick Tate, the chief executive of the School Curriculum and Assessment Authority, need not worry. Understanding one’s own cultural roots is an essential precondition to a wider international perspective.

If teachers are to lead the way to this ambitious vision, they will have to begin to perceive themselves as global citizens.

If this sounds like romantic claptrap, it is worth bearing in mind that it is already true in the worlds of business and finance. How else could a bank have been brought low by a deal in Japanese derivatives struck in Singapore by a financier from Watford?