Aarhus University Seal

Brad Wray presents "Setting limits to Chang’s pluralism"

16th International Congress on Logic, Methodology and Philosophy of Science and Technology, Prague, 5-10 August 2019


Hasok Chang has raised some serious questions about the extent to which there needs to be consensus in science.  At its core, Chang’s project is normative.  He argues that there are many benefits to pluralism.  I argue that Chang’s pluralism overlooks the importance of consensus in science.  I advance an account of consensus in science that will aid us in better understanding the constructive roles and limitations of pluralism in science. Chang argues that progress in science has been undermined and developments have been delayed because scientists have frequently been too quick to abandon a theory for a new competitor theory (see Chang 2012).  Chang illustrates this with a number of case studies, including what he regards as the too-hasty abandonment of the phlogiston theory in the late 18th Century.  He maintains that some insights contained in the phlogiston theory needed to be rediscovered years later. Chang argues that we need to foster pluralism in science.  The type of pluralism that Chang defends is broader than theoretical pluralism.  Chang is concerned with what he calls “systems of practice” (Chang 2012, 253).  He presents two families of arguments in defence of his pluralism: arguments that appeal to the benefits of tolerance, and arguments that appeal to the benefits of interaction between competing theories or scientific practices. Chang explicitly relates his defense of pluralism to Thomas Kuhn's endorsement of theoretical monism (see Chang, 2012, 258). I argue that Kuhn’s account of science allows for a certain degree of pluralism. Kuhn came to argue that the locus of consensus in a specialty community is the scientific lexicon that scientists employ in their research. A scientific speciality community is characterized by its use of a scientific vocabulary that those working in the specialty employ in their research. Kuhn was quite insistent that the scientists in a specialty must share a lexicon. The lexicon is what makes effective communication possible. Such a consensus, though, is compatible with significant differences between the scientists working in a specialty. In fact, such differences play an integral part in Kuhn’s account of scientific change. Kuhn was insistent that exemplars are open to multiple interpretations. It is their flexibility, their ability to be applied in a variety of different ways to different problems, which make them so useful to scientists in their normal research activities. Second, Kuhn argued that the values that scientists appeal to when they are choosing between competing theories are also open to multiple interpretations (Kuhn 1977). Again, this flexibility was crucial, according to Kuhn. It was the key to understanding the success of science. I argue that lexical monism is compatible with Chang’s pluralism of systems of practice.


Chang, H. 2012. Is Water H2O? Dordrecht: Springer.

Kuhn, T. S. 1962/2012. Structure of Scientific Revolutions, 4th Edition. Chicago: University of Chicago Press.

Kuhn, T. S. 1977. The Essential Tension. Chicago: University of Chicago Press.

Kuhn, T. S. 2000. The Road since Structure, Conant and Haugeland, (eds.). Chicago: University of Chicago Press.

Link to conference