E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Sure as Demoivre.
Abraham Demoivre, author of The Doctrine of Chances, or Method of Calculating the Probabilities of Events at Play, was proverbially accurate in his calculations. It was Pope who said, Sure as Demoivre, without rule or line.
Sure as a gun, as fate, as death and taxes, etc. (See SIMILES.)