“It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own self-interest. We address ourselves not to their humanity but to their self-love, and never talk to them of our own necessities, but of their advantages”       Adam Smith

Self-interest is the motive force which impels humanity forward.

Self-interest is all too often given a bad rap and not appreciated for the essential role it plays in our well-being. 

People often mistakenly consider self-interest and altruism as mutually exclusive and polar opposites. A more careful investigation however will reveal that self-interest necessarily incorporates altruistic elements, unless it becomes narcissistic. 

Enlightened self-interest considers the well-being of others as part and parcel with its own. 

The marine who throws himself on a hand grenade to save his comrades is acting out of self-interest in the sense that he values the lives of his fellow more than his own and is acting accordingly.