“Historically substantive” and “empirically examinable”

Historically substantive

Means:

important enough to tell us something significant about the historical process being studied.

For example:

“People sometimes disagreed.”

is historically weak and vague.

But:

“The abolition of slavery transformed the legal status of millions of people while leaving major social and economic relationships unresolved.”

is historically substantive because it identifies a significant transformation and an important unresolved problem.

Empirically examinable

Means:

capable of being investigated using evidence from the historical world.

For example:

“Formerly enslaved people experienced unequal access to land.”

You can examine:

• land ownership records;
• government reports;
• contracts;
• census data;
• historians' studies.

Therefore it is empirically examinable.