There are four non-duplication-related reasons to suggest closure of a question:
- off topic
- subjective and argumentative
- not a real question
- too localized
Should questions ever be closed for any of these reasons on a site about philosophy, wherein argument is seemingly inherent and everything is up for debate?
Regarding my assumption: See my answer about the provability of things in philosophy. It reflects my doubt in concepts like "real questions have answers" and "questions that are not answerable — discussions, debates, opinions — should be closed as subjective". Furthermore, we have yet to agree on whether this site is for doing or simply discussing philosophy. If it's for doing, then how isn't everything up for debate?*
*Also note: I fully support the use of up and down voting by the community to help visitors see where the real meaty discussions are taking place, I'm simply wondering if we should really ever CLOSE a discussion.