The precautionary principle brings a special challenge to the practice of evidence-based public health decision-making, suggesting changes in the interpretative methods of public health used to identify causes of disease. In this paper, precautionary changes to these methods are examined: including discounting contrary evidence, reducing the number of causal criteria, weakening the rules of evidence assigned to the criteria, and altering thresholds for statistical significance. All such changes reflect the precautionary goal of earlier primary preventive intervention, i.e. acting on insufficient (...) evidence, the least amount, or minimum level, of evidence for causation. Evaluating the impact of these changes will be difficult without a careful study of how well the current methods of causal inference work, their theoretical foundations, and the ethical implications of their applications. That research program will be most productive if it is jointly developed by public health professionals trained in the ethics and philosophy and by bioethicists and philosophers trained in the theories, methods, and practice of public health. (shrink)

Rolston (1988) argues that in order to act ethically in the environment, moral agents must assume that their actions are potentially harmful, and then strive to prove otherwise before implementing that action. In order to determine whether or not an action in the environment is harmful requires the tools of applied epistemology in order to act in accord with Rolston’s ethical prescription. This link between ethics and epistemology demands a closer look at the relationship between confirmation theory, particularly notions of (...) plausibility, in the philosophy of science and environmental ethics. Upon taking this look, I conclude that, at least logically, we are no better off assuming that actions are maximally risky (Rolston) than when we assume minimal risk. “Our vulnerability to error is greatest not from the things that we include in the model, but from the prophecies we leave out entirely.” Francis Bretherton “What is the main epistemic problem concerning science? I take it that it is the explication of how we compare and evaluate theories, as a basis either for theory acceptance or for practical action.” Bas van Fraassen “We face two kinds of ethical difficulties. One is where we know what ought to be done but not how to get the company to do it. The other is where we do not know what is right. We do not know the facts, or how to weigh the facts, especially statistical ones. We do not know the probabilities for development of future technologies. We do not know how to attach values to facts, or how to trade this good off against that one.” Holmes Rolston. (shrink)

The introduction of genetically modified (GM) crops and foods into Europe has generated considerable controversy. Despite a risk assessment system that is intended to beprecautionary in nature, the decisions thathave been taken have not gathered publicconfidence. Key attributes of a precautionaryappraisal system include humility,completeness, assessing benefits andjustifications, making comparisons, allowingfor public participation, transparency,diversity, and the ``mapping'' of alternativeviews rather than the prescription of singlesolutions. A comparison of the European GMregulatory system with a different (moreprecautionary) approach using a ``multi-criteriamapping'' technique reveals (...) a number ofproblems. These include the narrow framing ofthe established risk assessment system (therebyexcluding many issues of public concern), alack of public involvement in the process, anda failure to include appropriate comparisons ora diversity of options. Recent changes to theEuropean regulatory system only go part of theway to addressing these issues. Furthercontroversy may therefore be expected. However,practical ways of undertaking a morebroad-based precautionary approach are nowavailable (including the multi-criteria mappingmethod). These new approaches to technologyassessment offer a means for decision making toearn greater public confidence in this complexand difficult area. (shrink)