In 1913, Freud published the book "Totem and Taboo". This book was an attempt to reconstruct the birth and the process of development of religion as a social institution. He wanted to demonstrate how the study of psychoanalysis is important in the understanding of the growth of civilization. This book is about how the Oedipus complex and incest taboo came into being and why they are present in all human societies. The incest taboo rises because of a desire for incest. The purpose of the totemic animal is not for group unity, but to re-enforce the incest taboo. The totemic animal is not a symbol of God, but a symbol of the father and it is an important part of religious development. Totemism originates from the memory of an event in pre-history where the male group members eat the father figure due to a desire for the females. The guilt they feel for their actions and for the loss of a father figure leads them to prohibit incest in a new way. Totemism is a means of preventing incest and as a ritual reminder of murder of the father. This shows that sexual desire, since there are many social prohibitions on sexual relations, is channeled through certain ritual actions and all societies adopt these rituals so that sexuality develops in approved ways. This reveals unconscious desires and their repression. Freud believes that civilization makes people unhappy because it contradicts the desire for progress, freedom, happiness, and wealth. Civilization requires repression of drives and instincts - such as sexual, aggression, and death instincts - in order for civilization can work.