An atheist used to be a person who professed a definite belief that there is no God. Over recent years I have seen the growth of such terms as weak and strong atheist and all sorts of efforts to mask the point that atheists have an active, assertive belief system.
What is the belief system for an atheist? If I don’t believe in the Australian Aborigine dreaming as the explanation for the origin of the universe, what does that say about any other beliefs or non beliefs I might have? To not believe in a thing does not imply a belief in something else, nor does it imply that I have a system of beliefs in something else. If I don’t believe in invisible pink unicorns, then that doesn’t mean I have a belief system based on the non belief of invisible pink unicorns.