The document discusses enlightened self-interest, which states that by acting to further the interests of others or one's group, one ultimately serves their own self-interest. It provides Google as an example, investing in affordable housing to improve its societal standing. It also discusses unenlightened self-interest and how selfishness harms groups. Enlightened self-interest considers both personal and social interests, influencing local and global levels. It concludes that acknowledging both self-interest and altruism allows everyone to gain through cooperation.