Erroll Morris is a documentary film-maker — a very good one at that, having directed Fog of War: Eleven Lessons From the Life of Robert McNamara. His column, “Zoom,” contains two posts that detail his fascination with a pair of Crimean War photographs by Roger Fenton.

The posts don’t have anything to do with arms control, but everything to do with the craft of inquiry: painstaking collection and cautious interpretation of evidence.

Which Came First, the Chicken or the Egg? Part One and Which Came First? Part Two