Each person ought to pursue his or her own self interest exclusively. Morality of selfishness. Our own duty is to do what is best for ourselves. Other people matter only insofar as they can benefit us. Makes a claim about morality, or about the way things should be.
Each person does in fact pursue his or her own self interst alone. Makes claim about human nature, or about thing are. This is not a theory of ethics, rather, it is a theory of human psychology.
A selfless consern for other people purely for their own sake.
Commonsense Moral View
It says that ones own interests and the interest of others are both important, and must be balanced against each other. Sometimes one should act in the interest of others; other times, one should take care of oneself.
Revisionist Moral Philosophy
Philosophy that says our commonsense moral views are mistaken.
Principal of Ethical Treatment
We should treat people in the same way unless there is a relevant difference between them.