Ancient Decisions That Shaped History

On the night before the Battle of Gaugamela in 331 BC, Alexander the Great’s chief diviner performed a sacrifice and read the omens as favorable. Alexander attacked at dawn and defeated an army three times the size of his own. The diviner’s name was Aristander of Telmessus. He served Alexander for fifteen years and appears in the historical record repeatedly — not as a curiosity, but as a decision-making resource Alexander used the way a modern executive uses a risk consultant.

The fact that this strikes us as strange says more about us than about Alexander.

What the pieces in this issue examine is not whether the oracles were right. They were sometimes right, often wrong, and occasionally so ambiguous as to be unfalsifiable — which, as the Delphic priests understood perfectly well, is a feature, not a bug. What they examine instead is the structural role divination played in high-stakes decisions: why commanders, emperors, and heads of state across cultures and centuries built it into their institutional processes, what function it served that purely rational analysis didn’t, and what happens when you remove it.

Consultation creates pause. Pause creates distance between impulse and action. That distance, it turns out, has measurable value — regardless of what fills it.

History is full of decisions that went badly because no one stopped to read the room. It’s also full of people who built elaborate systems for doing exactly that.

— The Editors