The first of UNESCO’s annual philosophy encounters, earlier this month, was in this category. Finding themselves at the last minute in competition for space, if not for red carpet, with Fidel Castro and the G7, hundreds made their way over four days to the gloomy hinterland of Les Invalides where the UNESCO headquarters is situated, proof that the organisation can touch a public chord.

The theme was what we don’t know. In an inspired gesture a teacher from the Paris suburbs brought along her class of seven year olds. Philosophy is, of course, written into the French curriculum, but only at baccalaureat level. This teacher’s point was that savants do not have a monopoly on the exercise of intellectual curiosity. People grow to maturity by pushing out the boundaries of personal knowledge and structuring their personal unknowns.

Barbara Ferenczi’s pupils had been thinking with her about Saint-Exupery’s The Little Prince. One who wanted to draw the prince’s planet and rose dispatched her “essay” in two lines. “We don’t know what we do not know. The End.”

Several classmates, preferring to write, were deep into science and philosophy. Why don’t we fall off the earth when it moves? Why is the world the way it is and not otherwise? Is the essential really invisible to our eyes?

For the 40 experts invited by UNESCO the things they personally don’t know and what they try to understand are found on the frontiers of science in astrophysics and medicine, in what we don’t know about modern history, whether communications technology can be put at the service of all, and - central to anyone in teaching as well as in research - how we circumscribe our ignorance.

Those present at the conference included many famous names: the philosopher Bernard Williams, now of Oxford and Berkeley, John Maddox, editor of Nature, Stephen Jay Gould, the American palaeontologist and brilliant public communicator of the use and the misuse of science as it relates to the origin and nature of Man, and Trinh Xuan Thuan, a famous astrophysicist resident in the United States.

Bridge-building into education, they reminded us that Socrates, in pushing out the frontiers of what we know, said humility was necessary. Descartes called it philosophic doubt.

Bernard Williams underlined that there were no questions a modern philosopher ought not to ask, but it should be recognised that there are some that are deeply troubling, since one of the properties of the humanist is to be hopeful about the human condition. Hypothetically, would we want to know that human aggression cannot be overcome?

The French philosopher, Michel Serres, deeply involved in how technology can be a democratic tool, reminded the audience that etymologically the verb to research is to go round and round in circles. For the researcher this is recognised as a necessary activity en route, with luck, to a new thought. Why in daily life - or the classroom - should it be scorned?

In the 50 years since its creation, the United Nations’ arm for co-operation in education, science and culture, continues to circumscribe its own ignorance. It was an ideological battleground for the Cold War and for decolonisation. It was almost sabotaged by bad management and the departure of the US and the United Kingdom in 1984-85.

But under the present director-general, Federico Mayor, UNESCO has been able to shut several doors on its past. It has propelled itself back into view as a valued world forum for dialogue and cultural co-operation in all its forms.

Why does Britain still remain outside the humanistic organisation whose famous charter it helped to draft in 1945? “Since wars begin in the minds of man it is in the minds of men that the defences of peace must be constructed”.

The present Government’s weasly words about budget difficulties are ignominious. Making the case in the Government’s terms, the Labour MP Tam Dalyell once said: “Membership dues equal the price of two tanks.” But making the philosophic case would be better.