Perspectives in Biology and Medicine

FROM EPISTEMOLOGY TO RATIONAL SCIENCE POLICY: POPPER VERSUS KUHN G. G. PINTER and VERA PINTER* Socrates suggests . . . that, while one judgement cannot be truer than another, it can be better, in the sense of having better consequences. —Bertrand Russell [1] Introduction The great discoveries in physics in the early part of the 20th century demonstrated that scientific theories do not provide certainty. Philosophers of science who theretofore had felt secure in the edifice built on the seemingly solid foundations of Newtonian cosmology found themselves without shelter. One of the practical consequences of this upheaval was a collapse of the customary view that science progresses through gradual accumulation of proven and permanent truth. Among those who attempted to construct new frameworks for understanding the power and limitations of science after the second world war, Karl R. Popper and Thomas S. Kuhn exerted primary influence. Although Popper's first and seminal work, Logik der Forschung, was published in Vienna at the end of 1934 (inscribed with the year of publication of 1935), his influence on Western thought was felt only after 1959, when the much revised English translation of his book, Logic of Scientific Discovery was published [2, 3] . In his early years, he was associated with but was not a member ofthe Vienna Circle ( WienerKreis) ofphilosophers, whose logical positivism he criticized. He spent the war years in New Zealand and then taught at the London School of Economics. Thomas Kuhn, 20 years Popper'sjunior, taught at Harvard, the University of California at Berkeley, and later at Princeton, where he was associated with the Institute for Advanced Studies. Correspondence: 9321 Dunloggin Road, Ellicott City, MD 21042. *Both authors are retired. Last affilations: for G.G.P., Physiology Group, Kings College, London (Strand), for V.P., Whipps Cross Hospital, London, UK.© 1998 by The University of Chicago. All rights reserved. 0031-5982/98/4102-1046$01.00 Perspectives in Biology and Medicine, 41, 2 ¦ Winter 1998 291 His well-known book, The Structure of the Scientific Revolution, was published in 1962, and its second enlarged edition in 1970 [4]. In this paper we give a brief description of the views of both of these philosophers on science. By necessity, this description is restricted to their epistemologies and omits many details of the complex systems of thought which these philosophers contributed to epistemology. Next, we point out similarities and differences in their approaches and express our views on their philosophies. Finally, we note the potential consequences of their different views as they might apply to practical science policy. The Epistemological Theses ofPopper and Kuhn Falsification is the word that calls Popper's views into the mind of many scientists. Indeed, this is one of the essential points that separates his view from that of most other philosophers. Another distinguishing feature of his thoughts is that he does not accept induction as a means of arriving at scientific conclusions. According to Popper, scientific theories and hypotheses cannot be justified : no logic or experiment can establish that a scientific statement is true. On the other hand, a logical conclusion or rigorous experimental or other observation—if incompatible with the scientific statement—can demonstrate its falsity. Thus, scientific theories can be shown to be false, and science progresses not by a gradual increase of established true statements or theories, but by the elimination of false ones. Every false theory, in turn, is replaced by a new one which, in addition to explaining everything that the old theory explained, avoids the errors in the old theory and—most importantly—adds new aspects to it and opens new vistas on the problem in question. With the new vistas, new tests suggest themselves, so that the new theory can again be subjected to new tests. Theories which have successfully survived many such tests are considered to have been corroborated , but their truth has not been established, as they will be subjected to many more tests in the future which they may or may not survive. In this endless process, eventually all theories will fail and be replaced by better theories that give ever better description of how things work in nature. In Popper's view, the source of a new...