my opinion... and you are free to disagree with it...
is that intelligent mature adults should be able to discuss anything and everything. Controversy does not equate to conflict... conflict is generally introduced by someone who is accustomed to getting his/her way by bullying, or by someone who does not know how to hold a civil exchange of ideas.

It is normal, expected and desirable for members of a large group to have many different opinions. It only gets weird when one of the following things takes place:

1) someone tries to impose his/her opinion on the whole group

or (and this is just a variation of the first kind of imposition...)

2) someone tries to impose his opinion on the group by enforcing a ban on expressing the opposing point of view. This usually comes after a float and sting expression of an opinion, followed by the rule that nobody is allowed to follow up with a conflicting opinion.

Note that I'm not imposing this on the group as a rule, I'm only expressing it as my opinion.

https://www.dropbox.com/sh/ey71h8ep047758h/AAC12jNM0Hz9Q8zsh5iDeqNHa?dl=0