In our series on atheism, we examine the question of non-belief in Antiquity. In the first part of this episode, we review Jan N. Bremmer's article in the Cambridge Companion to Atheism on the various ways certain philosophers spoke and defined atheism and/or agnosticism. We then discuss whether or not human beings can be moral without belief in god/gods. Are atheists immoral because of their unbelief? Is good behavior only possible for those who embrace religion? Can non-believers also live meaningful lives or is meaning only to be found through religion? Do people really need to rely on some kind of transcendent reality or supernatural entity(ies) to find true purpose? Ancient and modern critiques argue that morality and meaning do not require one to adopt a religious outlook on life.