In Structure, Kuhn first introduces paradigms as achievements that were both unprecedented and drew attention from rival scientific activities and was incomplete enough to leave scientists problems to resolve. He then elaborates that paradigms are models that guide research or traditions that historians use to describe …show more content…
In these sections, Kuhn calls paradigm "intrinsically circular" and defines it as "what the members of a scientific community share, and, conversely, a scientific community consists of men who share a paradigm" (Kuhn 175). While paradigms exist within communities, they can also be global, a characteristic Kuhn attributes to all natural sciences. He also adds the stipulation that paradigms exist primarily in mature subjects, and he designates younger fields that have yet to firmly establish a ruling paradigm as pre-paradigmatic. His differentiation between global and local, or community, paradigms helps to explain some of his usages of the term, as well as noting that some variations resulted from stylistic choices in his writing (Kuhn 181).
One important distinction Kuhn makes regarding paradigms is their incommensurability. Incommensurability is the inability to compare things from different paradigms, resulting from a communication barrier that arises from operating under the different paradigms (Bird). This also implies that those operating outside of the paradigm cannot appropriately comment on the work within it, because of its inherent incommensurability (Walker 435). Kuhn 's notion of incommensurability is a topic of …show more content…
Chemists of the 1800 's believed that in flammable substances and in the air existed a material called phlogiston. In their paradigm, phlogiston was responsible for combustion. For most of their researched endeavours, this paradigm worked. However, there was an anomaly: based on the paradigmatic idea that phlogiston is released when things burn, combustion reactions defied the conservation of mass; when substances underwent combustion, their mass increased, which is counterintuitive when one considers they believed a substance was released. Most chemists of the day overlooked this anomaly or attempted to explain it away as phlogiston somehow having a negative mass. To one scientist, Lavoisier, with the importance he placed on precision and belief in the idea of conservation of mass, this anomaly was significant and merited explanation. He realized the phlogiston paradigm could not be right, and sought to find a different answer to the problem of combustion. Through his efforts, his experiementation, and his careful measurements, as well as through the efforts of Priestly and Scheele, it was discovered that oxygen, a new kind of "air", plays an essential role in combustion. After some time, chemists let go of the phlogiston paradigm and embraced the oxygen paradigm; this is exemplary of a