DMcG, that tale about the mirror reminds me of the Mirror of Erised in 'Harry Potter And The Philosopher's Stone'. Whoever looks in it sees what their heart desires, not the actual truth.
But of course, each one of us views the world from the standpoint of our own experiences, upbringing and even genetics. I remember a few fascinating tutorials in Moral Philosophy at Uni, about The Truth, and Self-Evident Truths etc.
And how much can one judge a person if they act in antisocial ways if their background and family life have been horrendous? Back to the old 'Punishment and Blame' conundrum.
I do think one can modify one's opinions and erroneous beliefs, but only if one wishes to. (And the fact one wishes to means that too is a part of one's character...)

Donuel, I did not wish to imply that the Jews actually were behind the financial disasters in Germany between the Wars, only that the majority of the population thought so, and used them a scapegoats for their shame at defeat in WW1. Hitler built on this, and manipulated minds towards feeling superior and nationally proud again by his bizarre speeches. Not hypnotism, but charismatic persuasion.

My rather superstitious mother used to say just after the War that the Devil had got into Hitler (she was Irish!) but my father used to reply that it was nothing to do with the Devil, just evil minds and manipulation, and a whole people willing to be uplifted and carried away by opportunist rhetoric that chimed with their innermost desires. (Like the Mirror of Erised in fact)