Atheism may not be an ideology but there is a common set of beliefs (a belief not being faith-related, but simply a conviction and confidence in an assertion about the world) associated with atheism. That set might consist of rejecting religion, believing in evolution, etc. In other words, if you were to question all atheists in the world about certain views, there would probably be about 2-3 same ones that would echo. Those beliefs do then influence the way people behave. One example off the top of my head is that an atheist probably would not vote for a person running for office if the person believed in Creationism. (I'd fucking hope that's the case). If someone were to argue that atheism is not an ideology and say that there are requirements needed to label something an ideology, I wouldn't argue against it. The more interesting question that arises from Chronic's statement is why he feels the need to explicitly say it's not an ideology. It probably has something to do with atheists' distaste for groupthink and lack of independent thought in religious circles. Atheists want to believe that they've chosen their path for themselves, that they are independent and rational, and not "sheep". There is a superiority complex that comes with it that I don't expect Chronic or most atheists to admit. Hey, when I meet a very religious person, my superiority complex starts blinking. Atheists like to point out that atheism is absence of belief. But there's the faith-based belief and belief, as I stated, that you have a conviction about something. You have a conviction that God, in the Abrahamic sense, does not exist. In other words, you have a belief.