Did Abraham Lincoln need to draw as much blood as he did to preserve the Union? Or did he move too slowly for a cause such as abolition?
Did Harry Truman need to commit to the firebombing of Tokyo and the atomic incineration of the citizenries of Hiroshima and Nagasaki in the final stages of World War II? Was Winston Churchill's reluctant agreement to the devastating bombing of Dresden in the war's later days truly necessary?
People of goodwill will debate and disagree about the particulars forever. All the while, leaders must continue to make agonizing decisions within a moment of crisis. This requires building up a certain aptitude for moral calculus—building it up over time, through personal experiences, through a study of history, and through knowledge of one's own moral core.
Consider a question from an old ethics test for army recruits—one with application for wise leaders in most any field.
You are asked to imagine that you are a soldier driving a bus down a treacherously narrow mountain road. The mountain wall stands on one side. A 200-foot drop-off looms on the other side. As you round a corner, a small child suddenly dashes out into the middle of the road to retrieve a ball.
You must now operate on instinct, because there is time to do only one of two things: