That's the really special part. There's plenty of places to find people that have a differing opinion, but HN does the best job I've encountered of fostering good, substantive discussion.
It doesn't always work, but it works here more often and on more subjects than anywhere else I've found. That "more subjects" part is important too, since unlike a smaller more focused forum, you might find that someone you totally agreed with on one subject the day before is someone you are in complete disagreement with the next day, and this can go a long ways towards helping people to remember that if they disagree on the current subject, the other person is likely a rational, agreeable person that deserves the benefit of doubt when you've found yourself interpreting what they've said as extremely harsh, disagreeable or wrong.
I think this happens mostly because the site looks so boring on the outside to anyone but tech professionals and hobbyists and proper nerds. This discourages the majority of people who would otherwise bring immaturity to HN. Thankfully it's not yet had its Eternal September [1].
