It should be of interest to educators that the model of moral psychology upon which the "teach, don't preach" orthodoxy depends is now roundly discredited. The moral psychologist Jonathan Haidt in his recent book The Righteous Mind writes of the "rationalist delusion" that afflicted 20th-century thinking, with its misplaced notion that we form our moral decisions and values through reasoned thought. He contradicts the work of Lawrence Kohlberg, a psychologist who should be familiar to trainee teachers. My PGCE textbook promotes his ideas, summarising them thus: "Mature moral judgment is dependent on a capacity to reason logically: it develops as children's reasoning ability develops."

Put into practice, these theories expose pupils to an undue level of stress and difficulty. Instead of being given clear guidance at an emotionally vulnerable stage in life, children are expected individually to create their own idea of right and wrong, through a troubling (and damaging) process of trial and error. Go to most secondary schools, and you will not find a utopia of reasoning Immanuel Kants "constructing" their individual modes of moral reasoning. Our PSHE lessons inform pupils about the health dangers of cannabis, but we turn a blind eye when pupils come into lessons visibly stoned. We teach lessons on the need to foster a positive work ethic, but passively tolerate lazy, disengaged behaviour in the classroom. And we tell pupils about the need to be well-organised, but allow them to turn up to lessons ten minutes late with no books or stationery. 

Both the amoralism of progressive education, and the misguided notion of "value clarification", have done immense damage to the condition of British education. A new outlook is needed. A surprising starting point can be found in the work of criminologist James Q. Wilson, who was made famous by his "broken windows" theory of inner-city crime. He understood that to combat urban crime, cities had to provide an environment that cultivates virtue. In his 1993 book The Moral Sense, he applied this insight to the failing American school system. He wrote:

A moral life is perfected by practice more than by precept; children are not taught so much as habituated. In this sense the schools inevitably teach morality, whether they intend to or not, by such behaviour as they reward or punish. A school reinforces the better moral nature of a pupil to the extent it insists on the habitual performance of duties, including the duty to deal fairly with others, to discharge one's own responsibilities, and to defer the satisfaction of immediate and base motives in favour of more distant and nobler ones.

A timelier message for the state schools of Britain would be hard to find. However, the success of this message will require a cultural counter-revolution in British education. Half a century of creeping moral relativism needs to be reversed, and state schools (like their counterparts in the independent sector) will have to offer an unambiguously moral environment for their pupils. If this sounds radical, it should not. Simply upholding the standards of common decency would be a major step forward for many state schools. It may sound painfully old-fashioned, but modern educators could do with returning to a motto first heard when the Bishop of Winchester founded New College, Oxford in the 14th century: "Manners Makyth Man".