Hedonism is obviously the best ethical theory. Bentham had the right idea
Bentham developed hedonistic calculus. The foundation is a multivariate ethical vector space. He rationalized hedonism to the extreme. The passions are explicitly tempered for a calculated greater good.
No? Once reason restricts passion, the hierarchy collapses. An action that causes yourself mild pain, but pleasure of greater extent to others, is preferable to an action that causes many others pain even if it gives you pleasure personally. Reason demands you restrain yourself from the passions that would harm others. That’s not unilateral fealty. Axioms must be assumed, but the most powerful systems assume as few as possible, and leave most of the legwork to reason.