David Hargreaves is a man whose time has come. "Extraordinarily," he says, "I am doing something more exciting than anything I've done in my career before."
To echo Marx, academics usually describe the world; Professor Hargreaves, 68, a former Cambridge University professor of education, believes he has a real chance of changing it. What he is attempting is nothing less than the transformation of secondary education.
Under the auspices of the Specialist Schools and Academies Trust, he is leading a project to make a reality of personalised learning, an idea Tony Blair launched on a startled world in 2004 without quite knowing what it meant.
This is no ivory tower exercise. Professor Hargreaves works in collaboration with schools and headteachers across the country, exchanging ideas and assessing their results. The outcome is not some mighty academic masterwork, years in the writing, but a series of 30-40 page pamphlets, speedily produced and easily digested by teachers.
The overriding theme is that secondary schools should follow business in moving from mass production to mass customisation. Instead of trying to persuade customers they want a pre-determined standardised product, the company discovers customers' needs and wants and then designs the production and delivery systems to meet them. Professor Hargreaves believes schools should do something similar. It would entail, he argues, re-thinking almost everything: the school day, terms, lessons, classes, year groups, subjects and tests.
He draws his ideas not only from familiar educational thinkers such as Ivan Illich (who posited self-directed education and even the use of technology to support learning webs) and Howard Gardner (best known for his theory of multiple intelligences), but also from Peter Drucker (widely considered to be "the father of modern management"), the economist Joseph Schumpeter (who explained how capitalism advanced through "creative destruction"), business gurus such as Charles Handy and, above all, the innovations springing up in schools. "It has become evident to me," says Professor Hargreaves, "that heads are redesigning the system from below."
What emerges is a heady vision of the emerging 21st-century school. Pupils set their own standards and learning objectives, work in teams, assess their own and each other's work, sometimes work at home and sometimes in a further education college, give their views on what makes a good lesson, spend whole days on projects that deal with authentic, real-world problems and bring ideas for using the information and communication technologies that now dominate their private lives.
Meanwhile, teachers become mentors or coaches, commenting on students' work but not giving marks or grades. Subjects (in key stage 3 at least) are subsumed under "competencies" - learning, citizenship, relating to people, managing information - and "essential learnings" - thinking, communication, social responsibility. The boundaries of schools are blurred: they work with others in networks or federations, while key activities, even the work of whole departments, are franchised or outsourced.
Is this the return of child-centred education? "Absolutely not," Professor Hargreaves replies. "This is a long way from a sloppy waiting to see what the child comes up with.
"If you don't give students today a say in learning, you won't get very far. They have to be partners, but there should still be lots of challenge and pressure from teachers."
For Professor Hargreaves, this is the crown of a life dedicated to the argument that to succeed, comprehensives must move beyond an academic, subject-based curriculum. His Social Relations in a Secondary School (Routledge amp; Kegan Paul, 1967) was the first British study to use anthropological techniques, observing how children behaved instead of simply testing IQs and measuring social handicaps. He identified a "delinquescent sub-culture" in which "the awkward squad" created a mirror image of the school's dominant culture of academic success, with its own rules, language and badges of achievement. The answer, he then proposed, was to abolish streaming.
Then, in The Challenge to the Comprehensive School (1982), he advocated changing the curriculum to end, for thousands of children, "a destruction of their dignity which is so massive and pervasive that few subsequently recover". Schools, he argued, gave too much priority to intellectual- cognitive abilities, not enough to the aesthetic-artistic, affective- emotional, physical-manual and personal-social. Children should have many more opportunities to "experience success", he said.
Professor Hargreaves proposed ending public examinations at 16 and reconstructing the curriculum around a core of integrated studies, with no traditional subject labels, plus arts, crafts, sport and "critical study of the mass media".
Some of these ideas fed into his chairmanship of an inner London education authority inquiry, which became known as the Hargreaves Report (1983). He was then the most talked about educationist in England.
Proposals for more frequent units of assessment (the modular system) and for building improvement mechanisms into schools were widely followed. In 1988, however, the Conservatives' imposition of a highly traditional national curriculum killed innovation for a decade.
Professor Hargreaves laid out his wares again in 1994 in a book for Demos, then Labour's favourite think-tank. The Blairites adopted some of them - specialist schools, for example - but took little heed of his call for political leaders to take "a playful attitude to ideas and alternatives". To his disappointment, Labour increased the rigidity of the national curriculum and his brief period as chief executive of the Qualifications and Curriculum Authority (2000-01) failed to achieve significant change.
Yet, to his surprise, the climate has altered over the past five years. "I've never before met so many confident, innovative, risk-taking heads," he says. "They are asking how radical they can afford to be. They want a system redesign.
"I don't know whether the Government, which is used to a top-down approach, can find space for it. If it does, we have the potential to be a real world leader in transforming secondary schools."
The Challenge for the Comprehensive School by David H. Hargreaves (Routledge amp; Kegan Paul, 1982)
The Mosaic of Learning: Schools and Teachers for the Next Century by David H. Hargreaves (Demos, 1994)
Personalising Learning by David H. Hargreaves (6 pamphlets from Specialist Schools and Academies Trust, 2004-2006) www.ssat- inet.netresourcespublications.aspx
System Redesign - 1: The Road to Transformation in Education (Specialist Schools and Academies Trust, 2007) www.ssat- inet.netresourcespublications.aspx.