Definition

An agnostic atheist is defined as one who does not know for sure if any gods exist or not but who also does not believe in any gods. This definition makes it clear that being agnostic and being an atheist are not mutually exclusive. Knowledge and belief are related but separate issues: Not knowing if something is true or not doesn't exclude believing or disbelieving it.

Agnostic atheist can often be treated as synonymous with weak atheist. Whereas weak atheist emphasizes one's lack of belief in gods, agnostic atheist emphasizes that one does not make any knowledge claims—and usually, the lack of knowledge is an important part of the foundation for the lack of belief. ​Agnostic atheist is arguably a label which applies to most atheists in the West today.

"The agnostic atheist maintains that any supernatural realm is inherently unknowable by the human mind, but this agnostic suspends his judgment one step further back. For the agnostic atheist, not only is the nature of any supernatural being unknowable, but the existence of any supernatural being is unknowable as well.

We cannot have knowledge of the unknowable; therefore, concludes this agnostic, we cannot have knowledge of god’s existence. Because this variety of agnostic does not subscribe to theistic belief, he qualifies as a kind of atheist." -George H. Smith, Atheism: the Case Against God