Critical rationalism - the epistemology of trial and error

Critical rationalism is a school in the philosophy of science and in political philosophy centred around the work of the Austrian philosopher Karl R. Popper (1902-94). The Social Democrat Popper fled Vienna and the Nazis in the late 1930s to New Zeeland and established himself in London after the war.

Critical rationalism is characterized by the method of ‘trial and error’, applicable in all scientific disciplines, philosophy, or politics according to its adherents. In a problem situation, a tentative theory is advocated to solve the problem. Thereafter, all efforts should be directed towards displaying the falseness of this theory (falsification, error elimination), and when this has been done, we are in a new problem situation, but with increased knowledge. We have learnt by our mistake. This optimistic belief in the possibility of the growth of knowledge justifies the label "rationalism". Moreover, this rationalism is "critical", since a prevailing theory should always be exposed to a maximum of criticism. This, of course, is a particularly demanding requirement to the theory constructor i.e. a requirement to kill one's own "child". However, it is a crucial purpose of critical rationalism to de-personalize research and its theories: "I may be wrong and you may be right, and by means of critical discussion, we may get nearer to the truth of the matter".

The entry is centred around a number of construed theses of critical rationalism:

(1) Reality exists "out there" (philosophical realism).

(2) Life is too short to quarrel about the meaning of words or concepts (anti-essentialism).

(3) Even though reality exists, it is difficult to grasp; there are no "facts" in themselves (anti-positivism or anti-inductivism)

(4) Theories should be parsimonious; among two theories with equal explanatory power, the simpler one should be preferred (the virtue of simplicity).

(5) Theories, in order to be scientific, should in principle be falsifiable (falsificationism).

(6) The development of society should neither be explained on the basis of traits or motives of individuals or groups within it (reductionism), nor on the basis of emergent properties of society as a whole (holism). Instead, revealing unintended consequences is the way forward for social and political science.

(7) Belief in historicist process laws is the basis of modern totalitarianism, be it of a marxist or fascist nature. By contrast, reform of the "open society" should be guided by piecemeal social engineering.

The crucial feature of critical rationalism is probably its link from rather sophisticated methodological reasonings to a forceful political philosophy. As distinct from his positivist colleagues in the "Vienna circle", with whom he had also severe epistemological disagreements, Popper wished to connect his reasonings to the ominous political developments taking place outside the seminar room.

Read the entry "Rationalism, Critical" by Hans Mouritzen in International Encyclopedia of Political Science, (eds. Bertrand Badie, Dirk Berg-Schlosser & Leonardo Morlino), London: Sage 2011