Men Willingly Believe What They Wish

From Commentarii de Bello Gallico, Book 3, Chapter 18, covering events of 56 BC. The Latin original is "Fere libenter homines id quod volunt credunt" — literally "Men generally willingly believe what they want to believe." Caesar wrote the line as an aside explaining why Gallic warriors so readily accepted a false Roman deserter's report that the Romans were retreating: they wanted to believe it, and so they did — marching confidently to their defeat. A similar observation had been made centuries earlier by the Greek orator Demosthenes.