An article in the new History and Theory caught my eye (bolds and underlines mine):
Making Sense of Conceptual Change
History and Theory 47 (October 2008), 351-372
Arthur Lovejoy’s history of unit-ideas and the history of concepts are often criticized for being historically insensitive forms of history-writing. Critics claim that one cannot find invariable ideas or concepts in several contexts or times in history without resorting to some distortion. One popular reaction is to reject the history of ideas and concepts altogether, and take linguistic entities as the main theoretical units. Another reaction is to try to make ideas or concepts context-sensitive and to see their histories as dynamic processes of transformation. The main argument in this paper is that we cannot abandon ideas or concepts as theoretical notions if we want to write an intelligible history of thought. They are needed for the categorization and classification of thinking, and in communication with contemporaries. Further, the criterion needed to subsume historical concepts under a general concept cannot be determined merely on the basis of their family resemblances, which allows variation without an end, since talk of the same concepts implies that they share something in common. I suggest that a concept in history should be seen to be composed of two components: the core of a concept and the margin of a concept. On the basis of this, we can develop a vocabulary for talking about conceptual changes. The main idea is that conceptual continuity requires the stability of the core of the concept, but not necessarily that of the margin, which is something that enables a description of context-specific features. If the core changes, we ought to see it as a conceptual replacement.