Abstract

The precautionary principle (PP) is thought by many to be a useful strategy for action and by many others useless at best and dangerous at worst. We argue that it is a coherent and useful principle. We first clarify the principle and then defend it against a number of common criticisms. Three examples from nanotechnology are used; nanoparticles and possible health and environmental problems, grey goo and the potential for catastrophe, and privacy risks generated by nanoelectronics.