I define "reasonable uncertainty" as:

The point when I am in disagreement with someone and have the choice to:
1. Work and invest time and effort to expand my own understanding so as to convert my own ideas
so that we can get an agreement. (move towards the Agreement Point in green zone)
or
2. I can give up and go into the red/resentment zone in my diagram. I simply create a thought image that I believe,
such as "they won’t listen" and move on to my next failed relationship.
or
3. I can wait for more information to reveal itself, which could take years. But once found I can then pump that into
the conversation to get an agreement or until the other person uses option 2. on me in which case there is nothing I can do
in my view, unless we had an agreed process to address such a situation.

I define "reasonable certainty" as:

an agreement formed using an agreed framework. Where the topic was scrutinised with no room for obsequiousness, sycophants, or
abuse and priming. Just thorough debate till we nut out a subject and still leave it open to be revisited if new information comes to hand.