Historian Andy Horowitz reminds us that disasters are never simply events confined to a particular time or set of circumstances in this contribution to the “Covid-19 and the Social Sciences” series. Using the notion of “pre-existing conditions,” a phrase typically confined more narrowly to analyze individual health outcomes, Horowitz questions how we assign a beginning to the pandemic. Our choices in this regard will influence how the story of the pandemic is told, who is assigned blame for what, and what are indeed the lessons to be learned from the experience. He also suggests that in times that feel “unprecedented,” it is all the more important to use history as a way to understand the present and chart a path to the future.