A philosophical movement is the appearance of (or the increased popularity of) a specific school of philosophy, an identifiable tradition of philosophy, or a marked change in philosophical thought on a particular subject. A school is a group of people, especially philosophers, artists, or writers, whose thought, work, or style demonstrates a common origin or influence or unifying belief. These are the famous “-isms” of philosophy.

A movement or school may represent the broad views of many individual philosophers, even if they may not agree entirely in all respects, so it is more a diffusely organized or heterogeneous group of philosophers tending toward or favouring a generalized common goal. It may also consist of intellectual thought by several individuals on several related ideas or doctrines, and the distinction between schools or movements, and doctrines or theories is sometimes blurred.

For convenience, the major movements and schools can be classified under three main sub-headings:

Within these, the major movements and schools include: