In this set of theories, the religious mind is one consequence of a brain that is large enough to formulate religious and philosophical ideas. During human evolution, the hominid brain tripled in size, peaking 500,000 years ago. Much of the brain's expansion took place in the neocortex. This part of the brain is involved in processing higher order cognitive functions that are connected with human religiosity. Robin Dunbar argues that the critical event in the evolution of the neocortex took place at the speciation of archaic homo sapiens about 500,000 years ago. His study indicates that only after the speciation event is the neocortex large enough to process complex social phenomena such as language and religion. The study is based on a regression analysis of neocortex size plotted against a number of social behaviors of living and extinct hominids. Stephen Jay Gould suggests that religion may have grown out of evolutionary changes which favored larger brains as a means of cementing group coherence among savannah hunters, after that larger brain enabled reflection on the inevitability of personal mortality. Lewis Wolpert argues that causal beliefs that emerged from tool use played a major role in the evolution of belief. The manufacture of complex tools requires creating a mental image of an object which does not exist naturally before actually making the artifact. Religion requires a system of symbolic communication, such as language, to be transmitted from one individual to another. Philip Lieberman states "human religious thought and moral sense clearly rest on a cognitive-linguistic base". From this premise science writer Nicholas Wade states: "Like most behaviors that are found in societies throughout the world, religion must have been present in the ancestral human population before the dispersal from Africa 50,000 years ago. Although religious rituals usually involve dance and music, they are also very verbal, since the sacred truths have to be stated. If so, religion, at least in its modern form, cannot pre-date the emergence of language. It has been argued earlier that language attained its modern state shortly before the exodus from Africa. If religion had to await the evolution of modern, articulate language, then it too would have emerged shortly before 50,000 years ago." The purpose of this series of books on religion, mythology and theology is designed to illuminate the necessity to emphasize our common humanity and eliminate the battles and divisiveness that exist within the ongoing religious struggles. This book presents a discussion of the facts surrounding the evolution of human belief systems and is designed to be a general overview of the topic and provide you with the structured knowledge to familiarize yourself with the topic at the most affordable price possible. The level of discussion is that of Wikipedia. The accuracy and knowledge is of an international viewpoint as the edited articles represent the inputs of many knowledgeable individuals and some of the most currently available general knowledge on the topic, based on the date of publication.