The question of how ancient peoples understood and explained natural disasters — earthquakes, volcanic eruptions, floods, plagues — reveals the interface between religious worldview and empirical observation that characterizes pre-modern science.

Ancient explanations were not simply 'supernatural' in the pejorative sense; they were attempts to explain unusual events through the most systematic frameworks available. The Greek naturalist tradition proposed physical explanations: Aristotle explained earthquakes through the movement of air trapped underground; Thales proposed that the earth floated on water and earthquakes were the shaking of the water. These were wrong but were the product of systematic thinking about natural causation.

Religious interpretations coexisted with naturalistic ones and were not necessarily incompatible with them. The question 'what caused this earthquake physically?' and the question 'why did the gods send this earthquake?' operated at different levels of explanation for most ancient thinkers. The Athenian plague of 430 BC was attributed by Thucydides to natural causes while simultaneously being interpreted by many Athenians as a punishment for impiety — both explanations were simultaneously available.

The Roman state response to natural disasters was partly religious (consultation of the Sibylline Books, which prescribed propitiatory rituals) and partly practical (relief distribution, reconstruction). The Pompeii earthquake of 62 AD prompted substantial reconstruction; the eruption of 79 AD caught the partially rebuilt city in mid-restoration. The letters of Pliny the Younger to Tacitus describing the eruption and the death of his uncle (who sailed to help survivors) are the most vivid ancient eyewitness accounts of a natural disaster that survive.