Scientific method in environmental toxicology

Abstract

Environmental toxicologists, like all scientists, are presented with choices over the philosophical frameworks within which they work. However, most scientists do not receive formal training in scientific method and this may lead to inappropriate choices. The use of inductive and hypothetico-deductive approaches in science is described and the problems of each are discussed. Problems with induction include logical circularity and the selection of appropriate observations. Problems with hypothetico-deduction include generalizing from deductions, true predictions from false theories, the falsification of true theories, criteria for theory rejection, practical application in some sciences, and the potentially large number of unrefuted theories. Problems shared by both induction and hypothetico-deduction are the theory dependence of observations and the ahistorical nature of both of these explanations of scientific justification. The role of induction and hypothetico-deduction in environmental toxicology is discussed. Environmental toxicologists face two types of problems: (i) monitoring of the current fate and effect of a chemical, which is a historical and local problem that may often best be solved by an emphasis on hypothetico-deductive techniques; and (ii) prediction of the future fate and effects of chemicals, which usually has the objective of general applicability across time, species, and habitats, and may best be solved by an emphasis on inductive techniques. The systematic combination of both induction and hypothetico-deduction within a pluralistic framework is likely to yield the greatest progress in most areas of environmental toxicology.Key words: scientific method, induction, hypothetico-deduction, monitoring, prediction.