Facts have not always been facts, says Ralph Levinson, lecturer in science education at London’s Institute of Education. Today’s givens - oxygen’s flame-feeding properties, planetary movement - were once hotly contested theories. Yet unless teachers convey the complex nature of science, and students grasp it, the mythical formula Science = Truth will continue to pervade almost all science teaching. Or it will until citizenship enters the lab.

Since last September, many science teachers have been asked to include aspects of this statutory cross-curricular subject in their lessons. Those who try, says Levinson, soon face a series of contradictions: “Citizenship is about conflict resolution and discussing different points of view. In science, more than in any other subject, the teacher asks questions with quite definite answers, such as ‘what colour does litmus paper turn when you put it in acid?’ Science teaching has become so entrenched within a basis of certainties that it’s difficult for students to see that there could be different interpretations of the facts.”

If citizenship and science are to be genuinely integrated - not just “building on a bit of social comment on top of the science” - then almost everything about the way we teach science will have to change, says Levinson. He means curriculum content, teaching style and skills, and the atmosphere, physical layout and language of the laboratory. And as the man who ran the Wellcome Trust’s huge study of the way secondary science is taught (see details below), he should know.

Nearly half of all science teachers believe that their subject is “value free”, according to those in the 1,000-school sample interviewed by Levinson for Wellcome’s Valuable Lessons project. Even teachers prepared to go beyond the facts feel there is no time, no assessment technique and no reward to students or teachers for doing so.

And how would they go about it anyway? The last thing most science teachers want is to preside over a passionate battle of ideas, says Levinson: “A lot of laboratories are serious places where you do practical work with things like glassware. The teacher is at the front; it is difficult for people to talk to each other.

“In discussion you may step into an area where the teacher is no more knowledgeable than the student, and I think in science probably more than in any other subject there is this unequal relationship between the teacher who knows and the student who is there to gather knowledge.”

If combined science and citizenship teaching begin to question areas such as vaccination policy or animal testing, inevitably the amount of time for pure science teaching will decrease. And so it should, says Levinson: the secondary science curriculum is overcrowded and over-academic for most students anyway.

But all kinds of problems would still arise. How much science would be taught, and in what order? Debate founded on ignorance is pointless, Levinson agrees - but adds: “You need very little conceptual science to understand any reasonably deep discussion of the implications of genetic screening.”

Science teachers find it hard to accept this, not only because they themselves are graduates of an academic science training, but also because they feel very untrained for managing controversy. It’s not that they believe that Science = Truth, says Levinson; they simply feel trapped by an over-factual curriculum and a misguided focus on “balance”.

“When you talk to teachers about how to help students make a judgment, they often say: ‘It’s not our job to tell them what to think.’ Which is right.

But it’s not the point. Students need to understand how to weigh one argument against another; they need to learn how to distinguish between facts and opinion; they need to look at the consequences of an action.”

English, humanities and RE teachers frequently teach these techniques in the classroom, he says; in fact they sometimes practise them by discussing scientific or quasi-scientific questions which science teachers would be much better equipped to address.

If school departments shared their expertise, and teacher training developed it, both science and non-science teachers would be much better equipped to support students not only in citizenship and in the new-style popular science qualifications (for example the new AS science for public understanding) but also in being able to grasp the relationship between science in the lab and in the world around them.

Levinson says: “Science is not straightforward. It’s uncertain and tentative and scientific experts don’t always have answers that are right or wrong. We have to start from the values we desire, and see how the content emerges from that.

“There is a relationship between science and the moral and ethical world, and I think if children don’t understand that, then they have not understood very much about science.”

A summary of Valuable Lessons: Engaging with the Social Context of Science in Schools is available from the Wellcome Trust website: www.wellcome.ac.ukschools Resources for discussion at KS3:http:sycd.co.ukcan_we_should-we