'Most educated people are aware that there are limits of reason, such as situations where the facts are so thin that the only honest answer is "I don't know".'
Some of the value of historical study is that you get to discover just how ideas like "limits of reason" and "I don't know" as a valid answer come about in the first place, out of processes that have nothing to do with progress and advancement. This is the kind of historical relativism people start getting afraid of ("what do you mean there's no objective standards for most anything!"), but it's a result of historical inquiry that actually commends us to actually think about what we say, do, and take to be true. We can have conversations with one another only when we drop assumptions. History is key to all ethical conversation.
Some of the value of historical study is that you get to discover just how ideas like "limits of reason" and "I don't know" as a valid answer come about in the first place, out of processes that have nothing to do with progress and advancement. This is the kind of historical relativism people start getting afraid of ("what do you mean there's no objective standards for most anything!"), but it's a result of historical inquiry that actually commends us to actually think about what we say, do, and take to be true. We can have conversations with one another only when we drop assumptions. History is key to all ethical conversation.