Essay on the Principles of Translation is an important treatise in the history of translation theory. It has been argued in a 1975 book by Gan Kechao that Yan Fu's famous translator's dictum of fidelity, clarity and elegance came from Tytler. Tytler said that translation should fully represent the ideas, style of the original, and should possess the ease of original composition. The book provides the general rules of a good translation.