The article starts with the theses that it is the very concept of action that is at stake in many debates between philosophers and historians. Whereas in philosophy actions are conceptualized by reference to their beginning, namely their motives or intentions, in historiography the consequences of actions are much more in the focus of interest. Especially the debate about the dualism of structure and agency is characterized by different concepts of action. In the article it is argued that this dualism can be overcome by stressing the intentionality of collective actions. First, a concept of action is developed against the background of a theory of intentionality. Second, intentional collective action is distinguished from individual and social actions and an analysis of a collective we-intention is proposed. Third, it is argued that the development of social structures has to be understood by reference to intentional collective actions.