- This article is about incommensurability in the philosophy of science. For other senses of this word, see commensurability (disambiguation).
Commensurability is a concept, in
philosophy of science, whereby
scientific theories are commensurable if scientists can discuss using a shared nomenclature that allows direct comparison of theories to determine which theory is
more valid or useful. On the other hand, theories are
incommensurable if they are embedded in starkly contrasting conceptual frameworks whose languages do not overlap sufficiently to permit scientists to directly compare the theories or to cite
empirical evidence favoring one theory over the other. Discussed by
Ludwik Fleck in the 1930s, and popularized by
Thomas Kuhn in the 1960s, the problem of incommensurability results in scientists talking past each other, as it were, while comparison of theories is muddled by confusions about terms, contexts and consequences.
