Pseudoscience as a Negative Outcome of Scientific Dialogue: A Pragmatic-Naturalistic Approach to the Demarcation Problem

The demarcation between science and pseudoscience is a long-standing problem in philosophy of science. Although philosophers have been hesitant to engage in this project since Larry Laudan announced its demise in the 1980s, pseudoscience as a societal phenomenon did not disappear, and many policy makers and scientists continue to use the concept. Therefore, the philosophical challenge of explaining what pseudoscience is and how it differs from genuine science still stands. Even though it might well be impossible to identify all pseudosciences by means of a set of necessary and sufficient conditions, we can nonetheless, in a naturalistic fashion, establish that pseudoscience is a real phenomenon, diagnose recurring features and symptoms, and explain how these emerge. In this paper we argue that science builds on and emerges from interactive reasoning, a process that, under particular conditions, weeds out beliefs and practices that are not (sufficiently) justified. When people nevertheless think of these beliefs and practices as equivalent to or even better than the ones accepted by the scientific community, they are rightfully regarded as pseudoscience. We explain the processes by which beliefs and practices may degenerate into pseudoscience and discuss the implications of our demarcation approach for the understanding of pseudoscience.