1) Atheism has a long history dating back to ancient civilizations like Greece and India. Major developments include Darwin's theory of evolution which supported a naturalistic view of life's origins. 2) The two main bases of modern atheism are Darwinism and materialism - the views that life evolved through natural selection and that matter is the only substance in reality with no supernatural. 3) Arguments for the existence of God include those based on Islamic scripture and reasoning about design, complexity, and the need for a first cause or creator of contingent beings and laws of nature. Refutations of atheist positions also exist.