Work is for the sake of leisure. Happiness is the end of human beings. Happiness includes but is higher than justice. Happiness requires the fulfillment of specifically human tendencies or desires, the highest of which are social and scientific tendencies. The ruler can be relatively happy, but the philosopher can be supremely happy.
Happiness requires wealth and good luck.
Wealth is a means, not an end. The scientist who goes over in his mind what he already knows does not need anyone or anything outside of himself. The supremely happy scientist needs friends. We need friends to be good to. Communities are bound together by friendship.