paradigm until a better paradigm is commonly accepted. A Kuhnian approach to the study of societies is provided by the critical juncture approach to social order and change. Heraclitan: The Greek philosopher Heraclitus used the metaphor of a river to speak of change thus: "On those stepping into rivers staying the same other and other waters flow" (DK22B12). What Heraclitus seems to be suggesting here, later interpretations notwithstanding, is that, in order for the river to remain the river, change must constantly be taking place. Thus one may think of the Heraclitan model as parallel to that of a living organism, which, in order to remain alive, must constantly change. A contemporary application of this approach is shown in the social-change theory SEED-SCALE which builds off of the complexity theory subfield of emergence. Daoist: The Chinese philosophical work Dao De Jing, I.8 and II.78 uses the metaphor of water as the ideal agent of change. Water, although soft and yielding, will eventually wear away stone. Change, in this model, is to be natural, harmonious and steady, albeit imperceptible. Four Levels of Action: Will Grant of the Pachamama Alliance describes "Four Levels of Action" for change: individual friends and family community and institutions economy and policy Grant suggests that individuals can have the largest personal impact by focusing on levels 2 and 3. Types of change Social changes can vary according to speed and scope and impetus. Some research on the various types of social change focuses on social organizations such as corporations. Different manifestations of change include: Fabian change – gradual and reformist incremental amelioration after the manner of the Fabian Society radical change – improvements root and branch in the style of political radicalism revolutionary change – abrupt, radical and drastic change, with implications of violence and of starting afresh (perhaps most popular as a political bogeyman) transformational change – a New-age version of radical change, and thus difficult to define continuous change, open-ended change – change (allegedly) for the sake of change top-down change – reliance on leadership bottom-up change – reliance on the huddled masses From a systems perspective, change in a system can be organized based on whether it is internally- or externally-driven and non-structural or structural. As a result, a living (ecological, social) system can undergo four types of change: internally-driven non-structural: regular dynamics in any living system externally-driven non-structural: acclimation or acclimatization internally-driven structural: