The idea that the uncouth people of the Middle Ages thought the Earth was flat is a myth that has been propagating since the nineteenth century, intended to give us a quite unfair view of this vibrant and exciting period.
The myth that Christians in the Middle Ages thought the world was flat was given a massive boost by Andrew Dickson White's book, 'The Warfare of Science with Theology' published in 1896. This book has become something of a running joke among historians of science and it is dutifully mentioned as a prime example of misinformation in the preface of most modern works on science and religion.
The flat Earth is discussed in chapter 2 and one can almost sense White's confusion that hardly any of the sources support his hypothesis that Christians widely believed in a flat earth. He finds himself grudgingly admitting that St Clement, Origen, St Ambrose, St Augustine, St Isodore, St Albertus Magnus and St Thomas Aquinas all accepted the Earth was a globe - in other words none of the great doctors of the church had considered the matter in doubt. Although an analysis of what White actually says suggests he was aware that the flat Earth was largely a myth, he certainly gives an impression of ignorant Christians suppressing rational knowledge of its real shape.
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