The emergence of environmental legislation has led to an increasing demand for scientific evidence. However, critical technical issues are often dealt with by judicial interpretation of the law rather than rigorous analysis of data. Scientists are expected to present their opinions in legal arenas which are not suited to the evaluation of deterministic or stochastic models. The adversary process hinders objective review of the sum of empirical knowledge. Confusion of terminology, methodology and philosophy indicates a fundamental conflict between the scientific paradigm and the legal paradigm. The former must prevail if environmental controls are to be effective.