Operationalist Fallacies in Biology

This paper examines - from a realist perspective - the influence of phenomenalism and its offshoot, operationalism, on concept formation in biology, as well as its implications for science education. To this end, the basic tenets of phenomenalism, versus those of realism, are expounded. The influence of phenomenalism and operationalism on current biology is criticized for leading to the confusion of cause with symptom - a mistake known as the operationalist fallacy. This fallacy consists in accepting pseudodefinitions, i.e., the so-called operational definitions such as An acid is a substance that turns litmus paper red, and pseudoexplanations such as The weather got worse because the barometer reading dropped. Many instances of this confusion can be found in science. This analysis, however, focuses on biology; it starts with more or less blatant examples, such as behaviorism and the concepts of genotype and homology, turning then to much less obvious examples, such as the definition of selection in terms of differential reproduction, the concept of a species as a reproductive community, the concept of isolating mechanisms, and thus the relational concept of biospecies. While it is maintained that operationalist fallacies are always to be avoided in science, it is discussed whether at least some of them are permissible in science education.