Atheism is the absence of belief in the existence of any god. It is not a comprehensive doctrine or belief system, but rather a position on a single question: whether one or more gods exist or whether they don’t.
People who identify as atheists do not believe in the existence of any deity. This distinguishes atheism from theism — the belief that one or more gods do exist.
Atheism exists on a spectrum. Some atheists assert confidently that there is no god, a position sometimes called “strong” or “explicit” atheism. Others take a more passive stance, merely saying that they see no reason to believe in any god. This is known as “weak” or “implicit” atheism. These distinctions reflect varying degrees of certainty about the question.
Atheism is often contrasted with agnosticism. Agnostics maintain either that they themselves do not know whether there is a god, or that it is in fact impossible for anyone to know whether there is a god.
Atheism and agnosticism are not mutually exclusive. Some people identify as ‘agnostic atheists’, meaning that they are unable to say whether there is a god or not, but see no reason to believe in one.
Atheism has been present throughout history, though its expression and acceptance vary across cultures and societies. In some countries, atheism is very common but in many countries atheists are stigmatised and persecuted.
Many atheists are led to ground their worldview in secular philosophies, humanism, or scientific skepticism – focusing on evidence and reason as the basis for understanding the universe. However, atheism is not itself a worldview or system of belief. It is simply an answer to the question, ‘Is there a god?’