The History Boys, Lyttelton, National Theatre, London

Putting ideas in boys' heads: from one point of view, that's the definition of education. It's a mark, though, of the deep-seated mistrust of things intellectual in England that the phrase also has a distinctly dubious edge. The very idea of transmitting ideas was repugnant to the reactionary old public-school headmaster in Alan Bennett's first stage work, Forty Years On (1968), who preferred the term "schooling" to "education".

The ideological battle-lines are a good deal bloodier in The History Boys, Bennett's new play, which returns to a school setting - this time, a Yorkshire grammar school - and a group of formidably precocious sixth-formers (brilliantly cast and played) who are preparing for the Oxbridge entrance exams. The piece reunites Bennett with his frequent collaborator Nick Hytner, the artistic chief of the National, who here pays the material the deep respect of a high-spirited production that is wonderfully well attuned to the play's hilarity, its acute wisdom and its unforced intimations of pain, emotional isolation and understated tragedy.

The emotional centre of the piece is Hector, a mountainous, maverick English teacher with unorthodox notions of general studies. Richard Griffiths beautifully brings out the erratic, far-from-selfless humanity of a teacher who believes that "exams are the enemy of education, which is not to say that I don't think education is the enemy of education". His leanings are homosexual, and the boys, long-sufferingly tolerant, take it in turns to ride home and be groped by him on the pillion of his motorbike. They can cope. It's the powers-that-be that eventually take punitive offence on their behalf.

The play's early-Eighties setting allows Bennett to dramatise the first stirrings of the Thatcherite educational culture that became obsessed with "results". Hector's nemesis arrives in the shape of Irwin (Stephen Campbell Moore), a squeaky-clean young supply teacher, whose task is to put these boys in training for the history scholarship exam. In his philosophy, truth is the first casualty of exam-passing. It's a journalistic game - all a question of "angles" and clever inversions. Periodically, the play flashes forward to his post-teaching career as a disabled right-wing TV historian and to a later role in government.

The cast is virtually flawless. Superbly sardonic, Frances de la Tour's Mrs Lintott alerts the boys to the shocking possibility that they may be interviewed by a female don. Dominic Cooper is cockily charismatic as the sexpot who is the focus of everyone's desire, and Samuel Barnett is winning as a version of the adolescent Alan Bennett. The plays asks uncomfortable questions - such as, is it better to know about literature or to know some literature by heart? ButThe History Boys does not pretend that there are easy answers. Full of lightly worn profundity, the play is a delight - and an education.

Booking to 2 Sept (020-7452 3000)