I know I do it too often, but to start I feel the need to quote Tim Minchin, yet again. On the very real divide between faith and science, he has this to say:
Not only is it true, but it rhymes. Kudos to Tim.
So, because of the very nature of the two quantities - science and faith - I see no problem with asserting that Atheism (or Agnosticism) has nothing but all to do with Science's evidence-based philosophy. Put simply: Atheism (or Agnosticism) is the only scientifically supported 'belief system'*, I feel.
That's not to say, as I hear a few of you cry, that there aren't scientists who are also religious; because there are. I'm also not saying that science is reserved for (or only valid if coming from) the religiously unaffiliated, because that too would be absolute nonsense... (Read more of this post)