Self-interest, or rather self-love, or egoism, has been more plausibly substituted as the basis of morality.

An ethical person ought to do more than he's required to do and less than he's allowed to do

Money, not morality, is the principle of commerce and commercial nations

Money, not morality, is the principle commerce of civilized nations.

We believe ... her story has been motivated by her own self-interest.

People often say that this or that person has not yet found himself. But the self is not something one finds, it is something one creates.