ABSTRACT
I begin with a problem of practical epistemology which has become increasingly acute in recent years. There has been a growth of a sceptical attitude to the claims made by scientists-in particular those made by the scientific experts wheeled out by governments and industrial companies to reassure the public that some apparent harm, say a pollutant in the water, is not really that damaging to themselves or to the natural world. Such scepticism is often rational. However, if as sometimes happens, it results in a quite general disbelief in any claim made by science, such scepticism becomes dangerous. A rational environmental policy depends on taking seriously scientific claims about acidity in water, the depletion of ozone, global warming and so on. A general scepticism about science undermines the possibility of rational and well-informed action in response to these.1 The central place of science in decisionmaking about the environment raises a related long-standing and important problem concerning the role of authority in democracy. When is it rational and defensible for citizens to accept the judgement of another individual, the grounds for which they are not in a position to appraise? In what conditions, if any, is deference to an authority rational and ethically defensible? When is scepticism justified, and what are the limits of rational scepticism?
