Selfishness is being concerned excessively or exclusively for oneself or one's own advantage, pleasure, or welfare, regardless of others.
Selfishness is the opposite of altruism or selflessness; and has also been contrasted (as by C. S. Lewis) with self-centeredness.
But if by this social life the human person is greatly aided in responding to his destiny, even in its religious dimensions, it cannot be denied that men are often diverted from doing good and spurred toward evil by the social circumstances in which they live and are immersed from their birth. To be sure the disturbances which so frequently occur in the social order result in part from the natural tensions of economic, political and social forms. But at a deeper level they flow from man's pride and selfishness, which contaminate even the social sphere. (Second Vatican Council. Gaudium et Spes, 1965).