‘Atheism’ is a much simpler concept than ‘Christianity’ or ‘Hinduism’, but the word atheism is still used in a wide variety of ways.
This can cause confusion. Someone may announce that she is an atheist, and her listeners may assume she is one type of atheist, when really she is a different type of atheist.
So to clear things up, here are 17 kinds of atheism, organized into 7 sets. Some kinds of atheism can be combined in a person, and some cannot. For example, it is perfectly consistent to be an agnostic, narrow, friendly atheist. But one cannot simultaneously be both a passive atheist and a militant atheist.
This list is not definitive. There are many ways to organize and label different kinds of atheism.
AN interesting list.
I would disagree with this comment here:
simply because it appears to be redefining "militant" for more politically correct meaning.A militant atheist uses violence to promote atheism or destroy religion. (Often, the term “militant atheist” is misapplied to non-violent evangelical atheists like Richard Dawkins. But to preserve the parallel with the “militant Christian” who bombs abortion clinics or the “militant Muslim” suicide bomber, I prefer the definition of “militant atheist” that assumes acts of violence.)
combative and aggressive in support of a political or social cause, and typically favoring extreme, violent, or confrontational methods.
"a militant nationalist"
synonyms: aggressive, violent, belligerent, bellicose, vigorous, forceful, active, fierce, combative, pugnacious; More