In his mature writings, Kuhn describes the process of specialisation as driven by a form of incommensurability, defined as a conceptual/linguistic barrier which promotes and guarantees the insularity of specialties. In this paper, we reject the idea that the incommensurability among scientific specialties is a linguistic barrier. We argue that the problem with Kuhn’s characterisation of the incommensurability among specialties is that he presupposes a rather abstract theory of semantic incommensurability, which he then tries to apply to his description of (...) the process of specialisation. By contrast, this paper follows a different strategy: after criticising Kuhn’s view, it takes a further look at how new scientific specialties emerge. As a result, a different way of understanding incommensurability among specialties will be proposed. (shrink)

In the first decades of the twentieth century, the process of photosynthesis was still a mystery: Plant scientists were able to measure what entered and left a plant, but little was known about the intermediate biochemical and biophysical processes that took place. This state of affairs started to change between the two world wars, when a number of young scientists in Europe and the United States, all of whom identified with the methods and goals of physicochemical biology, selected photosynthesis as (...) a topic of research. The protagonists had much in common: They had studied physics and chemistry (although not necessarily plant physiology) to a high level; they used physicochemical methods to study the basic processes of life; they believed these processes were the same, or very similar, in all life forms; and they were affiliated with institutions that fostered this kind of study. This set of cognitive, methodological, and material resources enabled these protagonists to transfer their knowledge of the concepts and techniques from microbiology and human biochemistry, for example, to the study of plant metabolism. These transfers of knowledge had a great influence on the way in which the biochemistry and biophysics of photosynthesis would be studied over the following decades. Through the use of four historical cases, this paper analyzes these knowledge transfers, as well as the investigative pathways that made them possible. (shrink)