I began to realize that I believed countless things which I had never seen or which had taken place when I was not there to see – so many events in the history of the world, so many facts about places and towns which I had never seen, and so much that I believed on the word of friends or doctors or various other people.
—Saint Augustine, Confessions
The tale of the Trojan Horse might be apocryphal – no one knows – but it stands out as one of military history’s most famous cautionary tales about yielding to unexamined beliefs. The story goes that the Greeks, frustrated by years of waging an unsuccessful siege on the walled city of Troy, built a massive wooden horse, left it at the city gates as a parting “gift” to their putative victors, and pretended to sail home. Ignoring the naysayers (most famously, the prophet Cassandra and the priest Laocoön, both of whom warned their fellow Trojans that the gift was a trap), Troy’s leaders brought the horse inside the city walls. That night, thirty-odd soldiers who had been concealed inside crept out and opened the gates to the returned Greek army. The Greeks destroyed the city and slaughtered its citizens, thereby ending – and winning – the Trojan War.