the Merriam-Webster.com Dictionary defines atheism in two ways: “1) a lack of belief or a strong disbelief in the existence of a god or any gods 2) a philosophical or religious position characterized by disbelief in the existence of a god or any gods.”[1] Lexico.com (Oxford University Press) defines atheism as “Disbelief or lack of belief in the existence of God or gods.”[2] See: Definition of atheism
Atheism, as defined by the Stanford Encyclopedia of Philosophy, the Routledge Encyclopedia of Philosophy, and other philosophy reference works, is the denial of the existence of God.[3] Paul Edwards, who was a prominent atheist and editor of the Encyclopedia of Philosophy, defined an atheist as “a person who maintains that there is no God.”[4] See also: Strong atheism
Beginning in the latter portion of the 20th century and continuing beyond, many agnostics and atheists have argued that the definition of atheism should be a lack of belief in God or gods.[5][6][7][8] See: Purpose of redefining atheism and Weak atheism
Atheism has been examined by many disciplines in terms of its effects on individuals and on societies and these effects will be covered below.
As far as individuals adopting an atheistic worldview, atheism has a number of causal factors and these will be elaborated on below as well.