Technically, a like/dislike button could do. But it would make the debate much poorer.
Even arguing, people may have better things to say than "I don't like".
On other forums, the rule is simple: each discussion is in a separate thread (the moderator may merge similar discussions); once the relevant facts and opinions have been expressed, and the discussion turns into a shoots exchange or repetitions, the moderator may without warning or justification:
- delete the irrelevant mails
- close the thread
- ban the troll
First measure is quite effective to impose self restrain, since there is no point for a polemist in typing dozen of replies to see them disappear. Second one is usefull when the subject turn into a truly polemic and/or repetitive exchange. Third one is effective on large forum with thousand of contributors, only the banned fill the sanction.
Problem is, the workload for the moderator. It is appropriate on very large public forums with multiple moderators. It would probably not suit a forum with few contributors willing to fully scrutinize a research topic.
Other problem would be a complex technical migration to a new forum engine, and categorization of existing discussions into separate threads.