Historian: There is no direct evidence that timber was traded between the ancient nations of Poran and Nayal, but the fact that a law setting tariffs on timber imports from Poran was enacted during the third Nayalese dynasty does suggest that during that period a timber trade was conducted.
Conclusion
The fact that there was law enacted during the third Nayalese dynasty that set tariffs on timber imports from Poran doesn't suggest that timber trade between Poran and Nayal was happening at the time.
Evidence
You can find on today's statute books laws regulating activities that were once common but in which people no longer engage.
Evaluate
The critic is trying to point out that, .
For example, there might be laws on the books of some southern states regulating what slaveowners can do with slaves, even though slavery has been gone for almost two centuries.
What would the historian say in response?
She's probably say ...
Goal
Look for an answer pointing out that the historian's argument was about an activity happening at the same time as a law about that activity was enacted, whereas the critic's response is about how an existing law might refer to an activity that hasn't happened in a long time.