Natural revision seems so natural: it changes beliefs as little as possible to incorporate new information. Yet, some counterexamples show it wrong. It is so conservative that it never fully believes. It only believes in the current conditions. This is right in some cases and wrong in others. Which is which? The answer requires extending natural revision from simple formulae expressing universal truths (something holds) to conditionals expressing conditional truth (something holds in certain conditions). The extension is based on the basic principles natural revision follows, identified as minimal change, indifference and naivety: change beliefs as little as possible; equate the likeliness of scenarios by default; believe all until contradicted. The extension says that natural revision restricts changes to the current conditions. A comparison with an unrestricting revision shows what exactly the current conditions are. It is not what currently considered true if it contradicts the new information. It includes something more and more unlikely until the new information is at least possible.

翻译：自然修正看似自然：它以尽可能小的信念变化来吸收新信息。然而，一些反例表明它存在谬误。它过于保守，以至于从不会完全相信，仅相信当前条件下的内容。这在某些情形下正确，在另一些情形下错误。如何区分二者？答案需将自然修正从表达普遍真理（某物成立）的简单公式扩展至表达条件真理（某物在特定条件下成立）的条件句。这一扩展基于自然修正遵循的基本原则，即最小变化、无差别性与天真性：尽可能少地改变信念；默认情况下等同场景可能性；在未矛盾前相信一切。该扩展指出，自然修正将变化限制在当前条件内。通过与无限制修正的对比，可明确当前条件的具体内涵——它并非当前视为真但与新信息矛盾的内容，而是包含越来越不可能的要素，直至新信息至少成为可能。