A reconstruction of the normative dimensions of the use of the precautionary principle in the context of European policy and European law since the publication of the Communication of the European Commission on the Precautionary Principle in 2000 will be presented in this chapter. This reconstruction will result in an overall definition of the precautionary principle which is not specific for any particular EU policy and applies equally to virtually all European Union policy domains. The normative dimensions of the Precautionary Principle and its relationship to risk management decisions include: • a normative political dimension which consists of a invocation of the precautionary principle within a particular policy area, the choice of the level of protection, the choice and design of an appropriate regulatory framework for the implementation of the precautionary principle and the choice of the possible regulatory measures against the background of a proportionality constraint. • a normative dimension of the assessment of epistemic uncertainties at the science-policy interface with a view on the acquisition of new knowledge in the context of scientific controversies. • The choice of transformable normative standards under particular regulations, which will determine the acceptability of particular emissions or products. An overview is presented of a deliberative framework in which the invocation, implementation and application of the precautionary principle is explicated in terms of its normative dimensions of the policy process in relation to risk management decisions. This overview should be understood as an ideal-type of description of all relevant deliberation levels in relation to the precautionary principle. The architectural framework of interrelating deliberation levels ensure public responsiveness and accountability of public actors, whereby at the same time the different deliberation levels can ensure a particular quality of the outcome. The precautionary principle is essentially a deliberative principle which can guide discussions at the science-policy-society interface.