Conjectural history is a type of historiography isolated in the 1790s by Dugald Stewart, who termed it "theoretical or conjectural history", as prevalent in the historians and early social scientists of the Scottish Enlightenment. As Stewart saw it, such history makes space for speculation about causes of events, by postulating natural causes that could have had such an effect. His concept was to be identified closely with the French terminology histoire raisonnée, and the usage of "natural history" by David Hume in his work The Natural History of Religion. It was related to "philosophical history", a broader-based kind of historical theorising, but concentrated on the early history of man in a type of rational reconstruction that had little contact with evidence.