Unpack (Pack)

This was a word by request, but really from the phrase "to unpack a concept". As we know, I don't do phrases, so the question is whether "unpack" is being used correctly in this context.

Pack (unpack) came into existence as a noun c. 1225, having derived messily from Low German/Middle Dutch/Middle Flemish/Old Norse "pak" "pac" "pakki" etc. for a group of persons of low character. It started with merchants, but a pack of thieves might have been redundant, once. As the "group" evolved to a bundle carried by such individuals, it became another verbified noun of the act of making something into a bundle. Then by adding the prefix "un" (not) c. 1425, we get "not bundled" or more accurately "not making something into a bundle". [Ed. note: why did it take 150 years to get the things out of the bag?] So, "unpacking a concept" would be to undo the bundle or more figuratively, to unwrap the concept so one can get at the facets of the concept-bundle. So, the short answer is, yes this is a correct, if slightly expanded, usage of pack/unpack, but it is similar to the expression "mining an idea". "Unpacking a concept" does suggest that there is a finite number of segments within the concept that need to be taken out and addressed, while "mining an idea" has an unidentified number of segments that could be addressed (could be a good vein or nothing at all, but you won't know until you start looking at it), so the former is more definitive while the latter is more speculative. However, as these are both idiomatic phrases, whether one is more or less whatever is irrelevant since they are not being used for the specific meanings of the words. Nor is this a malapropism. Someone at some time deliberately matched "unpack" with "concept" (like "mine" with "idea") as an expanded and evocative usage descriptive of probably how tightly wound, obscure, opaque, etc. the concept was which required someone to carefully, methodically and deliberately dismantle the packaging so that we could get at and therefore understand the real issues inside, and now we are stuck with that pair. This is why I don't do phrases, and yet I seem to still find myself doing them....