Before I enter any argument/negotiation, I want to know as much as I can about my opponent. Just makes sense. Common ground is part of that. Well siad, McGH.

There are lots of scenarios, however.

Debate
Argument
Fight
War

If it's some friendly foolin' around over who's beer is better than whose, you'll run the gamut of everything from 'define beer' to 'it causes liver disease'. After a few dozen, the need for the argument gets lost. Then it's 'define bathroom' and 'it causes piss'.

Speaking of which . . . .