The big lie about evidence-based policy-making is that it’s based on evidence. Evidence no more produces and speaks for itself than cars decide their destinations. Policy-making begins when people perceive a need for a policy. Even when it is evidence which moves a person to speak for a policy, such evidence is always seen through the prejudices, preconceptions and presuppositions that every human sees the world through. The desire for objectivity in politics, while seemingly sensible, belies a terrible loss of self-confidence, and can typically hide what should be political decisions under the guise of ’science’.
I was trying to make the point that a lot is presumed about science’s ability to answer deeper political and moral questions, and of course that politicians and other officials are somewhat promiscuous in their use of ‘evidence’. It’s not an argument against evidence, though no doubt some people will read it that way.