Weak atheism is in contrast to strong atheism, in which the atheist makes the positive assertion that there are no gods, and theism, in which the theist asserts that there is at least one god of some kind. The terms atheist and atheism are usually used to indicate strong atheism.

The difference between "strong" and "weak" atheism might be summed up as follows: strong atheism is the belief in the lack of any god, while weak atheism is the lack of belief in any god.