Photograph by Bridgeman/ACI The Greek historian Xenophon recounts in his Symposium that one day Socrates was out walking with some friends when they were approached by Callias, a wealthy Athenian.

Elon Musk revealed he's currently reading Xenophon's 'The Persian Expedition'. This classic explores the resilience and leadership of 10,000 Greek mercenaries. Musk, who often recommends books on ...