This is another of our series of conversations on intellectual humility and historical thinking.  With me today is Joseph Manning. He is the William K. and Marilyn Milton Simpson Professor of Classics and History, Professor in the Yale School of the Environment, and Senior Research Scholar in Law.  Manning has a specialized historical focus on Hellenistic history, with particular focus on the legal and economic history of Ptolemaic Egypt. His research focus over the last ten years has concentrated on historical climate change and its impact on premodern societies more widely. He is the principal investigator of the US National Science foundation project:  “Volcanism, Hydrology and Social Conflict: Lessons from Hellenistic and Roman-Era Egypt and Mesopotamia.” He is also on the editorial boards of Studia Hellenistica (Leuven) and the Palgrave Studies in Ancient Economies. He has coedited several volumes, and is the author of numerous monographs, the most recent of which is The Open Sea: The Economic Life of the Ancient Mediterranean World from the Iron Age to the Rise of Rome (Princeton University Press, 2018), which was the subject of a conversation in Episode 164 of Historically Thinking. He is now at work on a major new work on historic climate change and its impact since the last Ice Age.