Policymakers regularly accompany their policy proposals with scientific claims, while campaigners also cite ‘the science’ to further their causes. In 2011, the British Medical Association, as part of its anti-smoking crusade, asserted that smoking in cars generates 23 times more toxins than you would find in a smoky bar. While the figure was impressively frightening, it was also untrue. So rather than the problem being too little trust in science, are too many inclined to trust the science too much? This Battle of Ideas debate filmed at the Barbican addresses the big question, do government, activists and campaigners need to stop hiding behind science and make their arguments in moral and political rather than scientific terms?