What is the relation between a human being’s ultimate selfish interest and ethics/morality?

Ethics/morality

The paper should be about a minimum of 1,000 words (no maximum).

Answer both of the following two questions with respect to at least three of the following thinkers: Plato, Aristotle, Augustine, Hobbes, Hume, and Kant. You can, if you like, use different writers for each of the two questions.
1) What is the relation between a human being’s ultimate selfish interest and ethics/morality?

2) When it comes to ethical behavior, what is the relation between feeling (passion, sentiment) and reason (understanding, logic)?