I wouldnt describe atheism or secular humanism as belief systems.<quoted text>
....Atheism is not a religion. Neither is secular humanism - unless you are willing to call any belief system a religion regardless of what it advocates.
They interest me because I do not have a set of beliefs. I consider that an unhelpful concept and not something I would do. People can of course perceive me as having a set of beliefs like anyone else, but I think thats their mistake as it impedes their understanding of how I think.
I see set of beliefs as being somewhat in conflict with what I do which is to believe something only to the degree and extent that it can be supported by reason and evidence. I think it more accurate and constructive to see beliefs as a consequence of what the person considers facts and the interpretations and implications of those facts (or truths). Having a 'set of beliefs' seems to me a specifically religious way of thinking, as if a belief can be held independent from evidence and reason instead of simply being a consequence of them.
So for me, neither atheism or humanism are belief systems. There's nothing systematic or ideological inherent in them.