I think that humanism is an addition to atheism? Like you might be a Christian, but then there are denominations. Possibly. And not that I think that atheism is a religion, but I couldn't find an analogy. Oh! Atheism is like the main Sims game, and then humanism is one of the add-ons, so you play the game through the humanist disk, but it's all based on whether or not you have atheism installed.