Can you possibly think that you are the first person ever to have presented me with that argument? Giving two versions doesn't improve it. Certainly there are simple facts that have been confirmed by tens of thousands of years of human experience; no one denies that. That isn't the issue at all. How could you possibly think that it is? With all due respect, that is a profoundly naive response.
But take the depression of 1929. There are endlessly many "explanations" of why it happened. Some are relatively objective attempts to explain it (Murray Rothbard's for example) and some are blatantly politically motivated. The first requirment for an explanation is that it be logical, self-consistent and consistent with accepted principles of economics (in the case of the depression but that raises the question of which theory of economics you will use). But multiple such explanations may exist. How will you eliminate "wrong" ones? Or verify the "right" one? You can't run the experiment over.
You did not qualify your statement. Next time, do so.
The fact is that history can be known for certain in many respects. There is truth in history. If there wasn't then eyewitness accounts at murder trials would not carry the weight that they do in our legal system. Certain things can be known for sure, e.g. George Washington was 1st president, Lincoln was assassinated at Ford's Theatre in April 1965, slavery and states rights were two major underlying causes of the civil war, many southerners fought to defend their homeland (e.g. Jackson, Lee) - not for slavery, etc. etc. etc. Primary sources reveal true facts that cannot be denied. There is true history - logic does not allow that there be 2 opposing or contradictory TRUE accounts of the exact same event. That violates the law of contradiction and the law of contradiction is irrefutable.