Max Weber (1864-1920) was a German sociologist who studied social action and developed theories of bureaucracy, ideal types, and rationalization. He identified four main types of social action - goal-oriented rational, value-oriented rational, affective, and traditional - and recognized that most behavior involves a mix of motivations. Weber also developed the concept of ideal types to allow for historical comparative study and described bureaucracy as a rationally organized means of carrying out social action through a hierarchy with specialized roles and standardized rules of conduct.