If you look at history. It really is the conquerors who write their version of history which will be very biases at times. I think it is very interesting that foxes book of martyrs comes from a period where he was in favor to write the way he did. When he wrote it. It was during a favorable period middle 1500's, which became poplar to praise people and also prejudice people. It is filled with half truths. How much can it be on the other side too.
You would need The objective Truth. The only way you come close is to read both views. But then we have our biases whether we want to admit it or not.
What 's that argument about history. The conquerors bias?