"The present moment is where stewardship is testable."

We can directly observe how today's government or society treats the territory and its inhabitants.

Example.

Ancient kingdom:

We may know little.

Present government:

We can examine

courts,

elections,

taxation,

infrastructure,

civil rights,

education.

Those are observable.

So "testable" means

capable of being evaluated using present evidence.

Notice this is a political principle, not a rule of historical method.

History asks

What happened?

He is asking

What should matter most politically?

Those are different questions.