As a great thinker of France in the 18 th century,Voltaire’s "reason" is an ability to distinguish "good" from "bad","truth" from "falsehood".Voltaire regarded it as a kind of social political ethics,calling people to advocate reason and civilization as well as to oppose theocracy and barbarism.Therefore,it became the "yeast" of the French Revolution."Reason" is the important basis of his social political ethics,and he created The Orphan of China based on the Chinese Zaju The Orphan of Zhao in the Yuan Dynasty to express the "reason" that civilization is bound to defeat barbarism as "truth" and "good" are bound to defeat "falsehood" and "bad".Voltaire used "discipline" in The Orphan of Zhao as the "text" to advocate his rational political ethics.The text is chosen due to Voltaire’s favor for Chinese political ethics.