Dr Heeson is based in Amsterdam, where 10 years ago he set up a centre for teaching philosophy to children. He is the guiding force behind a pan-European journal of philosophy that, unusually, draws exclusively upon the thoughts of primary pupils. Journal 100 is funded by Brussels, through the Socrates Comenius Action 1 programme. Earlier this month, Dr Heeson was in Manorbier School in Pembrokeshire, South Wales, to launch its latest edition.
"Children of five won't have all the facts at their disposal, but if you listen to them in the playground they have the same forms of argument as an adult, and these can be developed," he says. "In Holland I heard two very young children discussing whether giants were real and one of them said 'In the world they're not real but in a book about giants, they are.' Now that is a philosophical discussion.
"The problem that five-year-olds have is not intellectual but social. In a class of 20 or 30 children they can't cope with argument so we have them in groups of three, four or five and that helps them learn to listen to others, to respect each other's views, to challenge and support each other."
Dr Heeson has edited the resulting discussions into the multi-lingual Journal 100, which takes its name from pioneering work done before the war by Janusz Korezak who ran a Polish orphanage with its own autonomous children's tribunal and journal of children's writing.
Manorbier is the only British school contributing to Journal 100. Karen Morris is the philosophy co-ordinator at Swansea University who initiated their involvement. "Berrie approached us with his idea and we chose Manorbier because of its commitment to introducing the subject right from nursery up to the top class - and because I'd been in to train the staff three years ago."
The philosophical discipline used at Manorbier is based on the pioneering work of Professor Matthew Lipman who, in 1969, left his post teaching aesthetics at Columbia University in New York to work out a curriculum for introducing philosophy to children. Ms Morris has adapted his work by adding picture books to stimulate philosophical inquiry in youngsters.
Although the notion of bringing picture-book Plato and elementary Rousseau into the nursery may sound absurd to the uninitiated, the subject is spreading rapidly through Britain because it fulfils many of the criteria laid down by the Office for Standards in Education. In recent years, OFSTED inspectors have praised philosophy highly because it combines speaking and listening skills with the development of critical and creative thinking along social, moral and spiritual lines.
The latest edition of Berrie's journal was put together in a way that the great philosophical minds of the past would find intriguing. At Manorbier, the class sits in a large circle with a member of staff acting as the facilitator. This "community of inquiry" has it own editorial committee of children who edit the transcribed debate and fax or e-mail
it to Berrie Heeson. He then translates - but does not amend - the work before it is printed in six languages: Italian, Dutch, English, Portuguese, Catalan and Polish.
The latest edition of Journal 100 inevitably repeats itself as six different groups try their hands at the range of questions. "What does it mean to do philosophy?" elicits some good answers, as does an exploration of fantasy. "How do we know we're not fantasy?" asks nine-year-old Jake from Manorbier.
However, a suggestion that every pupil write a thank-you letter to the artists of the world has the young philosophers struggling to comply. They have been over-directed here and accept unquestioningly the premise that art is good and artists are there to be thanked.
Nevertheless, six-year-old Cristiana from Catalonia is inspired by the question to make the endearingly wise pronouncement that "art is something we all have inside the heart but nobody knows what it is".
Tom Woods from Manorbier is one of the contributors to the latest edition.He's a sensible 10-year-old who likes the subject because "if you've got something you've been thinking about all week you can say it and hear what the others think".
Tom's favourite inquiry was into the question of whether toys could come alive. "Some people said they can't because they're made of fluff. But we did an experiment where we each brought in a toy and a biscuit and then left them in the classroom overnight. In the morning we counted how many biscuits there were and some had gone, including mine. But I don't really think my toy had come alive and eaten the biscuit, not really."
Ammeke Kateman contributes to the journal from her home in Holland. She's now 12 and has been studying philosophy since the age of nine. Last year she became discontented with the journal's method of working. "I did not like the questions they proposed because I like more to think about my own theories instead of answering questions."
Already Ammeke has read Sophie's World and she will probably continue with the subject in secondary school. "The first year I took philosophy in school I was planning to study it but now I want to become a film director."