In the third and final episode, Dawkins explains why Darwin's theory is one of history's most controversial ideas.
Dawkins uses this episode to discuss the opposition that evolution has experienced since it was first discovered. He starts by approaching various anti-evolutionists, ranging from John Mackay from Creation Research, Wendy Wright, President of Concerned Women for America, to English school teacher Nick Cowen. In order to address concerns they bring up, he shows the evidence for evolution, including fossil and DNA evidence. He also talks to the teachers of the science students who he taught during the first episode, asking them why they aren't adequately teaching the ideas of science properly, allowing instead their students to believe that truth is personal and that science is merely a point of view.
Dawkins also describes Darwin's personal loss of faith, based not only on the natural mechanisms he saw, but also on the cruelty in the world which seemed to deny a loving God, in particular the loss of his daughter Annie. While Dawkins does address the bleakness of the Darwinian view, he spends the last part of this episode describing how Darwin and he himself address it, ending by saying:
In the perspective of the universe, the vastness of the universe and of geological time, we are insignificant. Some people find the thought disturbing, even frightening. Like Darwin, I find the reality thrilling.
