Abstract
A fundamental tenet of Paul Feyerabend’s pluralistic view of science has it that theory proliferation, that is, the availability of theoretical alternatives, is of crucial importance for the detection of anomalies in established theories. Paul Hoyningen-Huene calls this the Anomaly Importation Thesis, according to which anomalies are imported, as it were, into well-established theories from competing alternatives. This article pursues two major objectives: (a) to work out the systematic details of Feyerabend’s ideas on theory proliferation and anomaly import as they are presented in his early publications and his Against Method and (b) to compare Feyerabend’s ideas on theory proliferation and anomaly import with corresponding features in Popper’s critical rationalist philosophy of science. As it turns out, neither the Principle of Proliferation nor the Anomaly Importation Thesis are necessarily incompatible with critical rationalism. In spite of Feyerabend’s general anti-Popperian attitude, I argue that theoretical pluralism can be seen as an advancement of the critical rationalist philosophy and that critical rationalism provides good arguments for pluralism.