In the comments on a posting to another blog, one reader argued that atheism is a worldview because it "answers the big questions in life."
The issue of whether atheism is a worldview seems to come up from time to time. And that issue depends upon two cans of worms: the definition of "atheism" and the definition of "worldview." I commented on the meaning of "atheism" in a previous post. I'm not sure there is widespread agreement regarding the meaning of "worldview." In a book review of David Noebel's Understanding the Times, I quoted Christian philosopher Ronald Nash who defined it this way, "A well-rounded world-view includes what a person believes in at least five major topics: God, reality, knowledge, morality, and humankind." David Noebel defines the concept in an even more expansive way. Probably the most noncontroversial statement that can be made about the idea of a "worldview" is that it includes a belief about ethics or morality.
On that basis, atheism alone is not enough to construct a worldview. Atheism does not entail any particular ethical theory; all that atheism entails is a rejection of theological ethical systems, such as divine command theory. Atheism is an important building block for various secular worldviews, however. For example, secular humanism is an atheist worldview, but it is not the only atheist worldview.