[R]ival paradigms are incommensurable …

Incommensurability means that there is no agreement about background assumptions, standards of evidence, hence, no common subject matter over which protagonists of opposing paradigms may have a proper argument … Common terms such as “entity,” “cause,” and “motion”—or perhaps “mercy,” “marriage,” and “conscience” in recent ecclesial controversies—may survive from one paradigm to the next, but a change in meaning has taken place. The terms no longer refer to the same things. A victorious paradigm does not advance, therefore, by refuting its predecessor. It succeeds, rather, by changing the subject, by no longer looking at the world in the same way or asking the same questions. The problems that preoccupied the old paradigm simply cease to be relevant anymore.

Michael Hanby. A False Paradigm, in the November 2018 First Things. Likely paywalled for a few more weeks.