Linda Slack is a self-confessed failure when it comes to science - at least, she was at school. With her good rote memory, she scraped O-level passes in chemistry and physics in the 1960s, then promptly forgot the lot.

She took a degree in contemporary literature and French and went on to become a health service manager. Interest in her children’s education and her work in a medical environment should have sparked some enthusiasm for science. “But it didn’t,” she says now, aged 61. “Not really.” Science remained a “closed door” for her, as it does for so many adults.

Then something happened. “I spotted the adult education course called Life the Universe and Everything at the Mary Ward Centre [in London] and signed up.”

The class, run by former A-level teacher Dr Andrew Morris, initially seemed little more than a discussion of things that interested the students. But, more than 10 years after signing up, Slack is still attending, along with many others, and confidently challenging claims made by experts including her GP, surgeons and dieticians.

If it had a profound effect on Slack, the course proved no less life-changing for Morris. His science and education credentials are impeccable: a doctorate in biophysics, X-ray crystallographer, teacher, chair of national education research organisations (including the Education Media Centre, which he helped to create) and a former director of City and Islington College in London.

Many people say his grasp of and vision for what works in science education is virtually unrivalled, including former education secretary Estelle Morris, with whom he has worked and advised at the Coalition for Evidence-Based Education at the University of York. Yet his long stint as an A-level teacher left him so disillusioned that he took up a life in management. “The approach to science was all about absorbing lessons - conformity, repetition, reproduction; adapting to a set of rules rather than being on a voyage of discovery,” Morris says.

But his passion for science and desire to enthuse others never left him. A chance conversation in 2002 with John Vorhaus, a friend who shared his vision and is now director of postgraduate research programmes at the UCL Institute of Education, resulted in the Mary Ward course. “I decided I should teach it within the humanities department, not as a traditional science - and they let me do it,” Morris says.

Unshackled from complex mathematics and unconstrained by the subject boundaries of biology, chemistry and physics, he started with the questions that interested students: “Why are clouds white?”; “How do sounds on the radio reach us?”; “How do vaccines work?”

The approach exploits the natural curiosity that too few people ever realise is at the root of good scientific enquiry; it resembles the natural philosophy of the Enlightenment from which “science” was born. And, after 12 years and hundreds of hours of discussion, Morris’ vision for the reform of science education was published this month in his book Getting to Grips with Science: a fresh approach for the curious.

“A fascinating observation, after several hundred sessions, is how unpredictable the pathway of discussion is,” he says. “Taking cues from the links people make from their experiences in everyday life, the path doesn’t follow conventional syllabuses at all, or even lie within discipline boundaries.”

Morris has also uncovered a basic misconception about how people learn. “The degree of complexity of topics people will pursue doesn’t follow the hierarchy associated with traditional syllabuses,” he says. “What teachers consider very basic ideas - such as gravity, the make-up of molecules or the nature of a chemical reaction - are not by and large understood and need careful handling. Yet discussion of, say, Heisenberg’s uncertainty principle or the role of DNA in genetics is welcomed.”

The proof of the pudding is in his students’ desire for more. “At the end of every year that I ran these courses, students would ask: `Can we keep going?’ So we moved to a wine bar, continued in a casual setting - they just keep coming.”

But despite the casual setting, there was no let up in the rigour. Melissa Rosenbaum, who quit science at school as soon as she could and is now another of the group’s lifelong learners, says: “We talk about things in an organic way; we start with a question and have a conversation until Dr Morris takes the reins to guide us in the pursuit of deeper knowledge. We read books, search the internet and visit real scientists at work.”

It’s an approach that many of the students think they should have been offered at school. Morris shares this view and is dismayed by the university-obsessed approach of so much school science. “Primary science is much closer to the things I am talking about,” he says. “It’s when you try to codify it into an examination syllabus that you run into problems. The upper-school syllabus is organised to suit the needs of those who will go on to study science, medicine or engineering. But what about the majority who need scientific literacy?”

In a chapter in his book on education for the 21st century, Morris points to developments from educationalists who are trying to create separate pathways for students who wish to specialise and for the vast majority who do not. His students are unequivocal in their views. As Rosenbaum says: “As a starting point, his is the best approach because it heightens your interest and you just want to go on. It feeds your curiosity.”

Getting to Grips with Science: a fresh approach for the Curious, by Andrew Morris, is published by Imperial College Press