Abstract: As a philosophical performance, the historical research of ideas focuses on grand ideas, which are "settled intellectual ‘products’" of a particular culture, and their historical development as well. The interest and motive of this research mainly lies in the belief that ideas are powerful. Major social ideas not only originate from the existing social relations but in turn reshape them. They may be powerful in persuading or moving persons, but it is also possible for them to be coercive and even violent. Ideas are powerful since they are logically "unclear" or "obscure", which makes them structurally different from "concepts". Hence, the abundant implications of ideas do not simply result from rational elements but also from emotional and volitional ones. The rational power of ideas impels theoretical expressions and even philosophical systemic construction, which will strengthen the persuasive power of ideas, whereas the emotional and intentional elements not only make ideas become moving but also actualized as material force in the process of institutionalization. Spreading from individuals to groups is necessary for an idea to realize its power, which is often enlarged because it frequently ignites trends of thought in a modern society. In this process, an idea itself will probably experience transformations at an intellective level. The realization of the power of ideas is eventually restricted by social conditions.

Key words: idea, history of ideas, power of ideas, persuasion, coercion