主题(theme),《欧美文学术语辞典》是这样定义的:“主题(theme)有时可以与‘题旨’互换使用。不过,这个词更常用来表示某个含蓄的或明确的抽象意念或信条。”“题旨”即指“母题”(motif)。在故事学上,“一个母题是一个故事中最小的,能够持续存于传统中的成分。要如此它就必须具有某种不寻常的和动人的力量。”“母题”也可译作“情节单元”。前苏联著名的民间文艺学家李福清就说:“我研究的方法有一个特点,从作品最小的情节单元入手,作系统性的研究。”可见, The theme, “Dictionary of European and American literary terms,” ​​is defined as: “A theme can sometimes be used interchangeably with ’subject’, but it is more often used to mean an implicit or explicit abstract idea or creed ”“ Theme ”means“ motif ”. In story, “a motif is the smallest element of a story that can persist in tradition, and in so doing it must have some unusual and moving force.” The Motif can also be translated as “ Plot unit. ” Li Fuqing, a famous folklore artist in the former Soviet Union, said: “The method I studied has a characteristic that begins with the smallest plot unit of the work and conducts a systematic study.” Thus,