Popper’s and Lakatos’s philosophies of science: main differences

The article compares Karl Popper’s and Imre Lakatos’s conceptions of the development of scientific knowledge. It is argued that the central difference between these conceptions relates to Lakatos’s thesis about the structure of scientific research programs as formed by a «hard core», which is «irrefutable» due to the methodological decision of the program’s proponents, and a «protective belt» of auxiliary hypotheses. From the standpoint of Popper’s critical rationalism, this thesis is unacceptable because it relegates critical discussion to the periphery of scientific activity; moreover, as Alan Musgrave and William Berkson have argued, the thesis is refuted by the history of science. The second important difference between Popper’s and Lakatos’s conceptions has to do with the definitive characteristics of empirical science (the «demarcation criterion»). An analysis of the debate over this issue suggests that a softened version of Popper’s demarcation proposal is preferable. This version takes into account Lakatos’s valid point that falsification depends on the emergence of better theories but repudiates his endorsement of «immunization» (against possible falsification) of the core theory of a research program. An interesting difference between Popper’s and Lakatos’s views concerns the issue of the possibility of a genuine logic of scientific discovery. However, on the one hand, Lakatos’s ideas in this regard were not sufficiently developed and clearly articulated in his published works, and on the other hand, attempts to develop these ideas by Elie Zahar and John Worrall demonstrate only the possibilities of rational historical reconstruction of scientific discoveries already made, and do not make a general «logic of scientific discovery» that could guide scientists in producing new discoveries. A number of other apparent divergences between Popper and Lakatos are rather differences in emphasis and focus of interest, and (as John Watkins shows) of Lakatos’s artificial and sometimes spurious contrasting of his ideas with Popper’s views.