Past exam of the philosophy of science supplementary subject of the University of Oxford / 2018 / 4 / b

Incommensurability can express several different claims. Rival scientific paradigms may organize terms differently, favour different exemplary problems, or rank standards of explanation differently. None of those claims by itself entails that their users cannot communicate or that no evidence can favour one account. Distinguishing these levels is essential to judging the claim rather than treating it as a slogan.

Semantic change is a serious possibility. In special relativity, distant simultaneity depends on an inertial frame; a Newtonian framework instead admits an absolute temporal ordering. Reusing the word “simultaneous” does not preserve every inference across the two accounts. A translation must identify which concepts and conditions correspond. That is more demanding than matching terms one by one.

Yet difference does not imply total incomparability. Observers can agree on local clock readings and compare predictions for specified experimental arrangements. In the low-speed domain, an appropriate limit relates many relativistic results to their Newtonian counterparts. Such a connection does not make the theories identical: it identifies a domain and an approximation under which particular predictions agree. It supplies a basis for comparison without requiring a complete, context-free translation of every theoretical term.

Methodological differences can also be real without making theory choice arbitrary. One framework may solve a familiar problem especially well, while another opens a wider range of questions. Accuracy, scope, simplicity and coherence can conflict, and applying them may require judgement. But shared measurements and successful novel predictions can still constrain that judgement. A disagreement over their relative weight is not evidence that every outcome is equally acceptable.

A defensible reading of Kuhn's revolutionary theory change therefore involves partial changes of meaning and standards, together with the work needed to understand a rival framework. It need not involve permanent mutual unintelligibility.^[ref] The strongest thesis, that rival frameworks cannot be rationally compared at all, is much less plausible: it would erase the distinction between changing conceptual resources and losing all evidential contact. The moderate thesis usefully warns against assuming that scientific change is always the addition of sentences to an unchanged language.