Howard Zinn said this quote
“ The willingness to undertake such action cannot be based on certainties, but on those possibilities glimpsed in a reading of history different from the customary painful recounting of human cruelties. In such a reading we can find not only war but resistance to war, not only injustice but rebellion against injustice, not only selfishness but self-sacrifice, not only silence in the fact of tyranny but defiance, not only callousness but compassion.Human beings show a broad spectrum of qualities, but it is the worst of these that are usually emphasized, and the result, too often, is to dishearten us, diminish our spirit. And yet, historically, that spirit refuses to surrender. ”