It reduced to one dictum, “Promote one’s own good”. This simply means look out for yourself. This person is always asking themselves “What’s in it for me?” This is all about self-preservation. An example of this is a political figure who promotes legislation that is in his best interest to gain political power or acceptance rather than the general good of the public. Ayn Rand was a proponent for ethical egoism. She thought altruism to be immoral. She believed you should only do well for others if you were going to gain something from it. One problem with ethical egoism is it does not promote altruism, which is praiseworthy, and inoffensive, promotes cooperation, and importance for relationships and the general human good.
Morality and self-interest overlap in many ways. You cannot have one without the others. If we honor our commitments, we will gain respect from others. If we help others, they are likely to help us when we are in need. Self-fulfillment is an important moral good because it requires moral commitments, long-lasting relationship, and community involvement. Also, if we are self-fulfilled then we have more to offer