Weak atheism is defined as simply the absence of belief in gods or the absence of theism. This is also the broad, general definition of atheism. The definition of weak atheism is used as a contrast to the definition of strong atheism, which is the positive assertion that no gods exist. All atheists are necessarily weak atheists because by definition all atheists do not believe in any gods; only some go on to assert that some or no gods exist.

Some people deny that weak atheism exists, confusing the definition with that of agnosticism. This is a mistake because atheism is about (a lack of) belief whereas agnosticism is about (a lack of) knowledge. Belief and knowledge are related by separate issues. Thus weak atheism is compatible with agnosticism, not an alternative to it. Weak atheism overlaps with negative atheism and implicit atheism.

Useful Examples

"Weak atheists do not find the evidence for the existence of gods persuasive. While theists say that deities, or gods, do exist, weak atheists do not necessarily disagree. Some simply hold no opinion on the matter. Others more actively have doubts that gods exist. They consider it likely that gods do not exist because no one can prove that they do. In this respect, weak atheism is similar to agnosticism, or the view that gods might or might not exist but no one can know for certain."

- World Religions: Primary Sources, Michael J. O'Neal and J. Sydney Jones