<< Then you would agree that Machiavelli's advice to the Prince was a
treatise on moral virtue? >>
This is actually a standard interpretation, but not because its advocatres think that self interest is a form of morality. M was a republican and a Florentine nationalist, an advocate of ancient virtue and modern methods. He urged Machiavellian methods as a way to create a strong Florentine state that he thought could promote the kind of regime he wanted and inculcate the ancient virtues into a free people. It has to be recalled that The Prince was written after the reurn of the Medici and the fall of the Florentine Republic inw hich M was an important diplomat, and for this reason a loser in the new order. He wanted to get in good with the new boss and still preserve the ideas of the regime that the Medicis had replaced andw hich served.
--jks