The old problem of egoism versus altruism often arises in this form: ‘Of course I have reason to pursue my own interests – but why should I respect the interests of others?’ We then seem to face a tension that everyone must wish everyone else to overlook. It must be a task of morality to try to divert us from the narrow path of self-interest along which reason points us.1 Two modes of response have the advantage of familiarity. One can try to make out that being moral is an investment that pays good dividends. As an edifying slogan proclaims from the cornice of Leeds Town Hall, ‘Honesty is the Best Policy.’ But this line of thought has two disadvantages: it tends to disingenuousness (‘It will pay you to be good’ probably means ‘It will pa...