Suppose we have a question
Why X?
and it has an accepted answer. Now suppose another user posts
Why X? Specifically, what is the mathematical description of X?
We might go ahead and mark the second question as a duplicate of the first. However, I'm not certain this is the best thing to do from a utilitarian point of view. The author of the second question does not seem to have a way of getting the mathematical perspective on X via the existing question for the following reasons:
He/she cannot accept a different answer on that question.
(Wrong! see below) He/she cannot draw attention to it by setting a bounty because there's already an accepted answer.
Posting a comment on the first question would get the attention only of the first question's author.
Even if the author of the second question could draw attention to his/her desire for a mathematical perspective, people are less likely to take time to write a nice new answer to the first question because there is less rep to be gained.
I'm wondering whether questions asking for a specific perspective on X should be allowed even if X has been explained previously.
What do you think?
Turns out you can set bounties on questions with accepted answers. Perhaps this is the best way to get new/different answers to these questions!