This chapter shows that theories of natural catastrophes in Greek and Roman literature in general presuppose the repetition of devastating events rather than their singularity, but that the ancient evaluations of natural catastrophes differ widely. Long shows that Plato and Aristotle tend to be detached and dispassionate in their accounts of such natural catastrophes by treating them simply as inevitable phases in the natural world’s cyclical history. By contrast, the Epicurean Lucretius and the Stoic Seneca clearly acknowledge human fragility in the face of catastrophes. Both philosophers register the dangers of presuming mastery over the natural environment and are sensitive to the human toll that nature can extort from exceeding such limits.