Relatively little of Berkeley's published work is devoted explicitly to the philosophy of ethics and politics. Berkeley did project a Part II of his Principles that would have included ethics, but he lost the manuscript while traveling in Italy in 1715, and Part II never appeared. This leaves Passive Obedience (a brief treatment of the duty to obey the sovereign), Dialogues 2 and 3 of Alciphron, which deal with the ethics of Mandeville and Shaftesbury, respectively, and various passages scattered throughout his other works. At the same time, however, a profoundly ethical interest infuses virtually the whole of Berkeley's corpus. For example, Berkeley begins the Preface to the Dialogues by insisting, against “men of leisure” who are “addicted to speculative studies,” that it should be a commonplace that “the end of speculation [is] practice, or the improvement of our lives and actions.” If his readers can be convinced by his arguments in the Dialogues, he adds, they will be shown how speculation can be “referred to practice” (DHP 1 [168]). The point is not that the Dialogues explicitly discuss practical matters; to the contrary, they are taken up almost entirely with issues of epistemology and metaphysics. Rather, Berkeley believes that only by refuting the doctrine of material substance can he establish securely the existence of a benevolent, “all-seeing God” and the immortality of the soul, both of which he thinks necessary to ground morality and secure it from the attacks and distracting counsels of atheistic, freethinking libertines (DHP 1[167-8]).