What is good? What is evil? In Chris Nolan's Batman, what separates one from the other are convictions which fluctuate as characters plod on with life. Villains and heroes are either side of the same coin. In the last installment of the trilogy, Nolan's message is clear. There is evil in all of us, even when we are good.
If we must continually battle with these warring tendencies, then what separates Batman from Bane? Both fight for a cause. Batman's heroism and Bane's anarchism both warrant a belief in humanity's capacity for redemption. Both have sacrificed their lives for their ideologies. Both teeter on that precarious divide between rule and order. Both act in the name of justice. So how is Batman different from Bane?
The answer, I think, is that he isn't. What separates the two are contingencies - differences in matter of degrees. Perhaps Bane has experienced just that bit more of pain and despair in his life. By accident he has met such and such people who have influenced him in this or that way. The film's surprise at the end highlights the similarities even more. Bane is Batman, in substance and in form.
If we acknowledge that there is in us both good and evil, that we are capable of both care and harm, then I think we would be more far more forgiving of others and of ourselves. An intolerance of this duality leads to impossible expectations. Idealism is cynicism's twin.