Big he may be, public-school hearty he is not. Tom Bentley, now aged 25, came to Oxford from primary and comprehensive schools in some of the most deprived parts of London. Part of what motivates him now, as he works on social exclusion at the Department for Education and Employment, and the think-tank Demos, is the knowledge that former classmates just as bright as he is may now be "housewives, or bank clerks - or in prison".
But Tom's particular middle class background - he is the son of a primary schoolteacher and a Church of England priest who worked in London's East End - gave him the breadth of education that most of his classmates lacked.
There was the art class on Saturday morning, the chess club and the basketball. Above all, there was his participation in the Inner London Education Authority's music scheme that led to his playing French horn in the London Schools Symphony Orchestra.
These extra-curricular activities, he says, helped him learn to get on with all sorts of people and gave him the ability to concentrate and to co-operate - skills often not fostered by conventional subject study.
He was also lucky in that his parents gave him access to a network of friends and contacts in other parts of London quite unknown to his classmates. It is this wide-ranging experience and openness that he wants to see in education for every child, described in his new book, Learning Beyond the Classroom, out next week.
This, he argues, "requires a shift in our thinking about the fundamental organisational unit of education, from the school, an institution where learning is organised, defined and contained, to the learner, an intelligent agent with the potential to learn from any and all of her encounters with the world around her".
He wants schools to become "neighbourhood learning centres", hubs of local learning and service networks rather than self-contained institutions.
Not that he is against rigour and centres of excellence. His own experience of doing English A-level under a consortium arrangement at Camden School for Girls showed him that good teachers can both motivate and be rigorous. But he wants reform to focus as much on the connections between schools and the communities they serve as on the internal effectiveness of the schools themselves.
Oxford, when he got there, was "a shock" - such a shock that he came close to leaving in his first year. The proportion of public-school pupils may have been lower at Wadham College than in the university as a whole but it was still about half.
Unlike them, he felt he didn't know how to "operate the codes". And, used to doing well, he found he lacked the study skills for his chosen course in Politics, Philosophy and Economics (PPE). He felt isolated and uncertain. But involvement in his college students' union, where he became welfare officer, and music (he played in the Oxford University Orchestra and in a band) came to his rescue and his intellectual confidence grew.
Undecided about pursuing a career in law, he decided to take a year off, go home to East Ham and try out a variety of jobs. Meanwhile, he won a prize in the 1994 Fabian Society Webb Essay competition writing on "The need for morality in public life". And he gained a place at the London School of Economics to take a masters in political theory on the area that had by now become his chief interest: the effect of political ideas on the policy process.
Then it occurred to him that he would be closer to the interface between ideas and policy at the fledgling think-tank, Demos. A tough interview with director Geoff Mulgan resulted in the offer of (unpaid) part-time work.
He supported his policy habit by working in the Regent Street branch of Gap."It gave me a grounding in reality," he says. After six months, Demos started to pay him - a little - and then he abandoned retailing.
Now a senior Demos researcher and tipped by newspapers as a potential director now that Geoff Mulgan is leaving, he also advises and writes speeches for David Blunkett, the Education and Employment Secretary. He is working on a range of issues, from early years to youth and employment, with a special focus on social exclusion.
His principal concern at Demos is also social exclusion, and he will be publishing three reports next spring. He relishes the difference between his two types of policy work.
"The discipline of working within government is how to achieve change - how it relates to the priorities the elected politicians set," he says. "At Demos, you have the freedom to think much more into the future and you are not constrained by the art of the possible - although your arguments are far more likely to hold water if you appreciate the art of the possible."
Without being either pompous or humourless, Tom Bentley is definitely serious-minded. ("I'm a Christian," he says, "but not a very churchy one. ") You feel the politics of spin are far from his concerns. But so too is pie in the sky.
"The agenda I set out is not a detailed blueprint, nor a utopian wish list," he says at the start of his book. "The argument is grounded in existing, practical examples. The seeds of solutions are already beginning to grow, and the current system can be progressively transformed by a process of evolution and innovation."
All his policy work leaves little free time. He is meant to spend two days a week at Demos and three at the DFEE but it can turn into three and four. None the less, he has just started playing his French horn again.