Actually, we only need to decide if we want to maintain the status quo or to change. The study of the past clearly hasn't worked to aid humanity in not repeating it. We repeat the same mistakes, even the grievous ones, time and again.
When will we stop killing one another over the fictions we tell ourselves? "We are the chosen", there is no God but Allah and Muhammed..." "all men are created equal and are endowed..."?
When? I bet most women, children and elderly people would love to know which fictions could bring us peace.