According to Marcus why were factions formed? Explain the belief of each faction as to why society failed?

During the ceremony, Marcus recites the history of the factions; long ago, people who blamed the trouble in the world on the faults in human personalities formed the factions as a way of reforming themselves. Those who blamed aggression formed Amity, those who blamed ignorance formed Erudite, those who blamed duplicity formed Candor, those who blamed selfishness formed Abnegation, and those who blamed cowardice formed Dauntless. He insists that without the factions, mankind would not survive.