To the ancient Greeks, religion was not just taken seriously—it was a matter of life and death. Religion was an existential exchange: through ritual, sacrifice, and pilgrimage, worshipers honored the gods just as subjects honored their kings. In return, the gods were expected to ensure fertility, health, prosperity, and victory.
This practical relationship explains the multiplicity of gods. Different needs called for different powers: rain from Zeus, victory from Athena or Ares, healing from Asclepius or Apollo. Religion was no mere symbolic gesture: the gods were assumed to exist—and their intervention was expected.
In return for good fortune and divine favor, the Greeks offered votive gifts—from small figurines to massive ships captured in battle—carefully housed within the sacred bounds of the deity’s temple. To tamper with such property was to invite swift retribution. The gods were not to be trifled with.
Which makes it all the more surprising to learn that Diagoras of Melos—the West’s first known atheist—once hacked a statue of Heracles to pieces and burned it as firewood to cook his meal.
Diagoras, a 5th-century BCE Greek poet and sophist, made it a habit to taunt the gods. In addition to using sacred statues to roast his lentils, he also mocked and revealed the secrets of the Eleusinian Mysteries—initiation ceremonies held annually for the cult of Demeter and Persephone.
This was no small provocation: Demeter was believed to have bestowed humanity’s greatest gift—agriculture itself. And what the gods gave, everyone knew, they could just as easily take away.
So if you were an atheist intent to prove you meant it, few gestures were bolder than testing the patience of Heracles and Demeter. Demeter could wither the crops and lay waste to the harvest, and Heracles—the son of Zeus—could unleash the full fury of his father’s lightning. These were not the gods and demi-gods you wanted to provoke.
But Diagoras noticed something crucial: when no misfortune followed his blasphemies, his confidence grew. He had rejected the gods—and nothing happened. No punishment, no retribution. Their supposed power began to look hollow, their stories more like folklore than truth. Diagoras had called their bluff—and won.
But he lost to those unwilling to part with their beloved myths. In the end, Diagoras fell alongside the gods he defied—charged with impiety and driven from his home. Misfortune did find him after all, though not at the hands of Demeter, but at the hands of democratic Athens. It wouldn’t be the last time.
In a more precarious age, where your very survival depended on the annual harvest, what could ever give you the confidence to challenge the god of agriculture? What made Diagoras so sure that the gods were mythological, and not active forces in the world with the power to erase entire populations with ease?
We can’t say for sure. The details of Diagoras’s life and thought are scarce. But the Roman statesman and philosopher Cicero offers a clue. In his book The Nature of the Gods, Cicero recounts the following story about Diagoras:
Diagoras, whom they call the Atheist, visited Samo-thrace, where a friend remarked to him: “You believe that the gods are indifferent to human affairs, but all these tablets with their portraits surely reveal to you the great number of those whose vows enabled them to escape the violence of a storm, so that they reached harbour safe and sound.” “That is the case,” rejoined Diagoras, “but there are no portraits in evidence of those who were shipwrecked and drowned at sea.”
The survivors, in other words, survived by chance alone—saved not by the gods, but by the law of large numbers. What’s more, Diagoras hit upon the cognitive bias at the heart of all superstition—more than two millennia before modern psychology would formally recognize it. Diagoras had discovered survivorship bias.
Survivorship bias is exactly what it sounds like: people pay more attention to examples of survival or success than to failures because the failures are hidden. Consider, for example, the temple of Poseidon, overflowing as it was with votive gifts and tablets from survivors at sea. But those who died at sea—in much greater numbers, despite their prayers—vanished like ghosts, never to be seen again. This created an illusion; a stroll through the temple made it look like the gods answered prayers, when, in fact, the majority of prayers were left unanswered. The gods were not required to explain any of this. All you needed was the most basic understanding of statistics.
And once you know how survivorship bias works, you see it everywhere. Diagoras himself probably noticed that things like drought, famine, shipwreck, military defeat, sickness, and death struck many people who otherwise made the requisite sacrifices and prayers. And yet the gods were ignoring far more people than they were helping (This would, down the road, create the nasty habit of thinking the victims of misfortune in some sense deserve their fate).
But biases run deep. And they exacerbate each other. Another bias—confirmation bias—amplifies the distorting effect of survivorship bias. People don’t just cherry-pick rare, favorable examples to make a point—they actively seek them out to reinforce the beliefs they already hold dear. For most ancient Greeks, the gods did answer prayers, and it was not hard to find examples to prove it. But it was all self-delusion.
Diagoras saw this with such clarity that he was willing to stake his life on it—and survived. He showed us that the gods do not help us, but they do not harm us, either. He might have dispelled our fears of the gods entirely. But we didn’t take the lesson. Two-and-a-half millennia later, and many of us still haven’t.
References
Aristopoulos, Dimitrios. “Diagoras of Milos: The First Known Atheist in History.” GreekReporter.com, December 9, 2025. https://greekreporter.com/2025/12/09/diagoras-milos-first-known-atheist/.
The Decision Lab. “Survivorship Bias.” Accessed April 6, 2026. https://thedecisionlab.com/biases/survivorship-bias.