Justin himself tells the story this way. It was the thirteenth year of the reign of Emperor Hadrian, 883 ab urbe condita. We would call it AD 130. Justin was in his early twenties, going for a walk near the sea – the Aegean, as he was in Ephesus, in Asia Minor. This was not just a saunter: he was a serious young man doing what serious young men love to do, which is to have a Big Philosophical Think.

Justin had a lot of material to work with. He’d been born in Flavia Neapolis, in Palestinian Syria, a pagan citizen of the Roman Empire. Beginning in his teens, he had felt himself to be on a philosophical quest: What is the nature of reality, of justice? What leads to happiness? And what about God? Or is it “the gods”?

Justin Martyr, like Socrates before him, was convicted of being an atheist.