What is atheism?

Atheism, at its core, is the absence of belief in any gods. This worldview can range from passively not accepting the existence of deities to actively asserting that no gods exist. In contrast, theism refers to the belief in at least one deity, creating a key distinction between the two perspectives.

Historically, atheism traces its roots to classical antiquity and early Indian philosophy. While it declined in the Western world with the rise of Christianity, atheism saw a resurgence during the 16th century and the Age of Enlightenment. By the 20th century, legal protections for freedom of thought helped expand atheism's recognition, with an estimated 500 million atheists globally as of 2003.

Atheist organizations advocate for secularism, the independence of science, and ethical frameworks without religious influence. Common arguments for atheism include the lack of evidence for deities, the problem of evil, contradictory religious revelations, and the assertion that extraordinary claims require extraordinary evidence.

There is ongoing debate over how to define atheism precisely. Some view it as merely the absence of belief in gods, while others see it as an active rejection of theistic claims. Atheism often overlaps with agnosticism, which is characterized by uncertainty about the existence of gods.

Atheism can be classified into implicit and explicit forms. Implicit atheists, such as young children, have not consciously rejected theism, while explicit atheists actively deny belief in gods. Positive (or strong) atheists assert that no gods exist, whereas negative (or weak) atheists simply lack belief in gods.

Throughout history, belief in deities was so widespread that atheism was often questioned. Some modern atheists, like Sam Harris, argue that the term "atheism" itself should be unnecessary, as it merely reflects a rational stance against unproven religious beliefs.