Based on what?

My son is currently adjusting to the change of education of moving from school to university.  One of the more interesting changes of how his chosen subject (history) is talked about can really be summed up in the question "based on what?".

Up until now, most of his textbooks have included an unchallenged narrative of events and decisions in history.  It would go something like "King Ichabod marched his armies to the Crane Valley, where he fought an unsuccessful battle with rebels.  He decided to move back to a resupply point in Sleepy Hollow to regroup for a second assault".

At University, much more is expected of him, and of his materials to prove such a set of claims.  For instance,

• How do we know he fought his battle at the Crane Valley?
• How do we know he lost?
• How do we know why he chose to move back to Sleepy Hollow?

These claims are based on what?  Basing them on what's been written in other books isn't a terribly strong to build your case on, you can only be as strong as the case they make.

I didn't get to study history quite as far as my son, but when I studied at advanced level, we were given this puzzle "does history really exist?".  The unnerving fact is that really it doesn't.  We can only make educated guesses at what happened X many years ago based on the evidence we have.

• We can have confidence a battle took place at Crane Valley based on contemporary accounts (of the time).
• If we go digging around and find grave sites and abandoned weapons - all of which match the period, that gives us more confidence (even so you tend to occasionally find some battlefields further away than they were believed to be).
• Who won is an interesting one - we generally only read about wars from the accounts of the final winners.  And it's been known for some people to rewrite lost battles in their favour.
• We can know something of what someone was thinking and feeling from letters they sent, their personal diaries, and speeches they gave (if recorded).  Even so, historic figures are well aware of the power of spin and self-delusion.  A defeated general on the run might well put the blame more on his troops than on himself.

Of course talking to my son, what interests me is this is key to being a good tester - to challenge the narration we're being given, by asking for proof and evidence where you can find it.  Whether for history, critical thinking or testing it's a mindset well worth exploring.