Abstract: As part of the history of sociology,the history of sociological thought approaches the historical evolution of sociological thought from the angel of intellectual history or sociology,and explains such an evolution aided by textual interpretations.The existent studies in the history of sociological thought can be roughly classified into either internalism or externalism,but such a framework itself lacks in-depth studies.Building on the debate between two American sociologists,Charles Camic and Jeffrey Alexander,this article compares their different positions on explaining the formation of ideas,the development of social theory,and the history of sociology,and then discusses three issues in the debate that are related to the internalist and externalist distinction.Finally,it delves into the meanings of internalism and externalism,their respective explanatory mechanisms,and their relationship.