What happens when a new discovery makes an old word stop giving us a clear answer? The problem is not simply that we lack information: sometimes the word itself seems to wobble. Established ways of talking can be unsettled by new developments, particularly when features once presumed to co-occur diverge.

These cases often involved ordinary words for things we can observe, and they had the flavor of science fiction. The discussion turns to cases outside science fiction that lack some of the extra theory surrounding the older examples. The central claim is that these cases resist explanations based on what people know or on what the world is like, and they are not simply familiar kinds of uncertainty in language.

That gives reason to think openness may be its own kind of problem, deserving its own explanation. Some cases involve classifying something new, while others involve reclassifying something familiar after new developments. Both can make people reconsider which statements show that someone understands a word.

Calling one case an extension of an idea and the other a sharpening of it may only redescribe an apparent difference. Changing the words would not remove the problem, because the question would return: do the new things really belong to the old categories? The cases produce an unstable experience: we are unsure what to say, and unclear what further information could settle the issue, while competing dogmatic inclinations pull us toward opposing judgments.

One reaction is being unsure what to say, with no clear extra fact that would settle the matter. The competing reaction is confidence that a competent speaker could not have been wrong, or that earlier speakers were mistaken even if their mistake made sense at the time.

Earlier classifications support one answer, while current classifications support another; reactions to new observations can remain confused or divided. If the present use of a word expresses a different idea from its earlier use, a strange result follows: people may have only recently begun thinking about the things that word names.

The cases produce an unstable experience and judgments that something remains continuous across the change. They are not clearly explained by a theory about how words acquire meanings, or simply by people lacking some knowledge. They also are not clearly just incomplete definitions, vagueness, uncertainty, or context doing the work, although language theories may still represent them that way.

The tentative conclusion is that openness is its own kind of phenomenon and deserves its own theory. One possible response is that people can coordinate a word’s meaning with a newly created use, even when they cannot state the resulting meaning in terms everyone accepts.

That ability lets people understand earlier speakers as sharing reasonable attitudes with people today, even when their words do not match today’s most common interpretation. The cases suggest there is no simple path from the forces shaping how people use a word to one definite meaning that everyone can know.

Instead, several competing explanations may connect a word’s use with the world and with speakers’ attitudes. For a word such as woman, people may disagree about whether it applies through sex, social position, felt identity, or something else. They may ask which properties the word has tracked over time, or which properties its reflective use should be intended to register in the relevant community.

Open texture describes cases where familiar words cannot settle new or changing cases, even when people understand the words perfectly well. That matters whenever new technology, science, or social change forces old categories to stretch.