Abstract: The history of ideas, aiming at studying some key ideas’ generation and development in human spiritual changes, is a part of human beings’ efforts to know themselves. Its task is to seek for true ideas, including truth of the idea content, consistency between the idea user’s actual belief and attitude implied in the idea, and real vitality of the idea pushing social actions forward. The history of ideas deals with not only the structure of thought but also its process, and focuses on not only the issue of how people should think but also how to think in reality. How to deal with the relation of “thought” to “history” is concerned with vertically how to solve the issue of the idea’s genesis and social rootedness, and horizontally how to find out the location of a certain idea in its contemporary idea family tree and the connection between the idea history and other academic studies. The history of ideas is never a chronological history which merely narrates “idea units”. The critical history of ideas pays close attention to various elements coming from the history of civilization, and the method of pedigree is equally important like logical analysis.

Key words: idea, history of ideas, true idea, pedigree