I am a historian and claim no particular expertise in the teaching of English. However, after consulting dictionaries, style manuals, and colleagues who teach English, I offer the following rules with the hope that they will prove helpful. In English . You need no article when you are referring to an entire class. Diplomacy is an interesting subject.
American religion is a topic with which most Chinese students are relatively unfamiliar.
History is usually understood and appreciated more by older students than by younger ones. In these sentences you are referring to a whole class with the use of the noun, and you therefore need no article at all. A diplomacy is essential for every nation. William James argues that every person has the right to believe in a religion . A national history is generally better understood by persons familiar with the nation and its culture.