a seriously fragile foundation to be resting an argument upon

Speaking of reality or any one's awareness (and "engagement") with it: Arendt described "reality" best, I think, simply by acknowledging in her works the mechanical (or perceptual) limitation of verification, essential to trust (equilibrium).

I cannot know what I cannot see. (tautology)

I cannot see what I do not know.

I cannot know what is not here.

Reality --events both worldy and mental-- is ahistorical and atemporal. One cannot be everywhere at once in order to verify what is true, what is false. The true fact one cannot verify everywhere at once does not preclude reality. It merely necessitates entrusting another. That is to assign verification of a person, process, or thing
by one's self to one or more agents (person, process, or thing).

All rationality --justified true belief-- depends on this "fragile" foundation of verification in order to explain itself to one's self.

Diversity is the key to economic and political evolution.

Addicts and libertarians alike either don't believe in consequences, don't want to believe in consequences, or believe that consequences don't apply to them.