ALTHOUGH the Government gives the impression that it only cares about what can be tested, it has over the past few years revised the national curriculum to decree that children be taught about values.

Citizenship education is now compulsory; the science curriculum has been revised so that students must learn how to weigh up ethical issues in science and technology. A recent Department for Education and Employment document boldly states: “No one believes (academic) achievement is the only important outcome of schooling. It is also important that pupils learn to know right from wrong, to get along with other children whatever their background; to make a contribution to the school as a community; to work in teams; to develop positive attitudes toward life and work”.

We should probably welcome this policy. Children ought to be able to think rigorously about their values, and society needs informed citizens who can think rationally about ethical issues. So teachers need to learn to teach about values. But there are two kinds of moral issue. There are issues about which we all - even psychopaths - know right from wrong. Children can easily be taught that murder, bullying, stealing from the poor, and torturing babies, are wrong. The problem is getting people to act on that knowledge, when they sometimes have self-interested reasons for doing otherwise.

The other kind of moral issue - where reasonable people disagree about what is right - is more problematic. Abortion, redistributive taxation, capital punishment, medical research using animals: in each of these cases there are reasonable people with serious moral arguments on both sides. But in each case, depending on your point of view, at least one side is wrong.

Pupils should “learn to know right from wrong” in such matters. But what role should schools play in this and how can they carry it out? One way would be to discover the truth, and teach it. I hope the problems with this approach are obvious. The school is an arm of the state, but it must not indoctrinate children. To do so would be an abuse of its power, which is only legitimate if it has the consent of the governed, and if that consent is not the result of indoctrination.

So what should schools do? Teachers should equip children with the reasoning skills and information needed to think rigorously about moral issues, and to reach their own conclusions. They should teach pupils how to identify arguments based on personal prejudices and appeals to the moral high ground, how to detect (and reject) bias, how to think logically, how the claims of social science work, and what the limits are of social scientific knowledge.

They should elicit the difference between self-interested and impartial erspectives, and enable children to detect these in their own arguments as well as those of others. They should ensure that children know what Christianity, Islam, socialist and conservative traditions have thought about moral issues, and what the reasoning has been behind that thinking. They should teach children how to attack someone else’s best argument, without getting personal feelings involved. Pupils should learn that the issues are subject to rigorous investigation. They should respect children’s own efforts to think matters through, without validating the widespread (and nonsensical) view that everyone’s opinion is equally valid.

And they should do this without indoctrinating children with their own or mainstream views, but also without misleading children toward moral relativism.

This is, obviously, a formidable challenge. And there is nothing in our current formal initial teacher training that prepares them for this momentous task. Nor does mass culture provide many resources. Public political debate is conducted through sound-bites and slogans. Ostensibly serious media debates like Radio 4‘s The Moral Maze abandon rigour for point-scoring and egotism.

Some trainee teachers come across excellent lecturers who guide them into the traditions of rigorous thinking about moral questions. Some get exposed to this before their PGCE by incorporating philosophy modules into their first degrees. But these are incidental to the process of learning to become a teacher, which gives no formal place to the pedagogy or practice of moral reasoning.

Teachers training for PSHE and religious education get some instruction in ethical reasoning, but not much. Ethical issues arise across the curriculum, and too often teachers fall into the trap of thinking that their duty to respect their students forces them to take a stance of “anything goes” moral relativism.

Philosophy is the discipline which develops the tools of rigorous moral argument, and philosophers are uniquely placed to teach about the complex issues involved in values education, because it is something they themselves do all the time.

The upshot, of course, is that if the Government is serious about getting “pupils to learn to know right from wrong”, and does not want the state to indoctrinate, it must ensure that all secondary teachers are trained in philosophy. It should give serious attention to how this requirement will be met. For example, will it mean a module in moral or political philosophy or informal logic in teacher training? Or will departments of education employ philosophers in initial teacher training? The Government is right that children should be taught about values. Their next step must be to help teachers do this.

Harry Brighouse is professor of philosophy of education at the Institute of Education, London University