The history of science reconstructs how scientific knowledge, method and institutions actually developed within the intellectual world of their own period, rather than reading past natural philosophy as an incomplete draft of modern science. The Belgian historian George Sarton founded the discipline's flagship journal, Isis, in 1913 and went on to found the History of Science Society in 1924, arguing that the history of science deserved sustained scholarly study in its own right, distinct from the potted origin stories scientists themselves told about their fields and from general history, which had mostly ignored science as a subject.
A sharp boundary between religion and science is itself a comparatively recent historiographical framing, and the history of science documents long periods and whole civilizations where astronomy, medicine and natural philosophy were pursued as religious activity rather than against it, Islamic astronomers calculating prayer times and the direction of Mecca, Christian monasteries computing the liturgical calendar, and Chinese court astronomers reading the sky for the Mandate of Heaven. The atlas relies on the discipline to describe these periods on their own documented terms, rather than importing a modern religion-versus-science framing that would have been foreign to the people who did the work.