Activism, in a general sense, can be described as involvement in action to bring about change, be it social, political, environmental, or other change. This action is in support of or opposition to one side of a controversial argument.
There are many different forms of activism; a select list follows.
... to Strasburg and Cologne and in the
Netherlands. He was a follower of Geert Groote
and Florentius Radewijns, the founders of the
Brethren of the Common Life. ...