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.
... (WRL), which he would remain a member until his retirement in 1999 (he remains active within the nonviolence movement and regularly participates in WRL ...