My home doesn't have a specific mission statement, or delineated rules for discussion. TFL does. Even so, I reserve the right to manage and direct discussions as necessary in my home. For example, if folks in my home get too rowdy discussing politics and religion, I can ask them to lower their voices, or change topics before things become too heated. Not all discussions are appropriate in all times and all places.
Well said Spats. My idea of a great time is having friends over for good food and conversation about things that matter. Discussion of these things, even among friends can sometimes get contentious. As the moderator/host I have the responsibility of seeing that the conversation remains civil. There are issues that some folks can't discuss calmly and civilly. Fortunately, I also have the freedom to control the guest list.