1. In philosophy, the problem of the circularity of understanding: where understanding A presupposes understanding B, which in turn presupposes understanding A.
2. In hermeneutics a dialogical relation between the part and the whole in texts: we have to refer to the whole to understand the parts and the parts to understand the whole (e.g. in understanding sentences and the words within them). This concept was introduced by Schleiermacher although the term was coined by Dilthey. In hermeneutics, it is seen as the path to greater understanding rather than a problem: unlike a ‘circular definition’, it is not meant to suggest ‘going round in circles’, since, as noted by the Greek philosopher Heraclitus (fl. 500 bc), ‘No man ever steps in the same river twice, for it's not the same river and he's not the same man.’ Some commentators therefore refer to the process as more like a spiral. It has been applied to the relations between texts and genres, between text and context, and between theory and data. Giddens refers to a double hermeneutic in which social scientists seek to engage with both emic and etic perspectives on social reality.
3. The poststructuralist, anti-hermeneutic notion that since all signs refer to other signs, no ultimate meanings can be established.