The concept of tradition, in early sociological research (around the turn of the 19th and 20th century), referred to that of the traditional society, as contrasted by the more modern industrial society. This approach was most notably portrayed in Max Weber's concepts of traditional authority and modern rational-legal authority. In more modern works, One hundred years later, sociology sees tradition as a social construct used to contrast past with the present and as a form of rationality used to justify certain course of action.