Conceptual Change: Rationality, Progress and Communication

Abstract

Conceptual change in science first became a hot topic five decades ago, when questions were raised about rationality and progress through scientific change. Among the first philosophers who raised these concerns, particularly in terms of the incommensurability thesis, were Thomas Kuhn and Paul Feyerabend. The main target of the incommensurability thesis was to reject the continuity of scientific change, which would ultimately question the progress of science, and rationality of scientific choice among rival scientific theories. Although philosophers of science have widely discussed this issue since the 1970s, a common understanding of conceptual change has been absent. What most scholars discussed were about specific cases of conceptual change, such as the change from ‘phlogiston’ to ‘oxygen’ or from the Newtonian use of the term ‘mass’ to the way Einstein employed it. With the heated discussion focused on these and similar cases, the notion of conceptual change per se has largely been overlooked.

The first and most well-known approach to explaining conceptual change, embraced by scientific realists, was the referential approach. This approach explains rationality and progress of science in terms of the stability of reference. In order to explain referential continuity, theories of reference borrowed from the philosophy of language. If reference stays stable across scientific change, then we can explain many complicated cases studies where the progress and rationality of science were questioned. However, in the first years of the twenty-first century, a younger generation of philosophers, mainly philosophers of biology, argued against the referential approach in favour of a non-representational approach. In fact, fixing a unique reference for some key biological terms is notoriously difficult, if possible at all. Therefore, the reference of some biological terms should be determined depending on the context of use and on user’s coordination intentions.

In this thesis, my main aim is to evaluate the strengths and weaknesses of the new non- representational approach to conceptual change. I argue that, while raising valid objections to the referential approach, the non-representational approach fails to explain communication and to fully vindicate rationality and progress in science. On demonstrating philosophical shortcomings of this new approach, I articulate my own framework for evaluating the adequacy of an account of conceptual change. Although proposing a new account of conceptual change is beyond the scope of this thesis, I briefly outline a possible way to meet the desiderata on an adequate account of conceptual change, opening a new space for further research to satisfy the proposed framework.