1. Aim and Scope of this Paper.—In this paper I shall try to show that “duty” derives its significance from its relation to “interest,” and that the former concept cannot be understood when taken apart from its relation to the latter. Such a doctrine is, I am aware, rejected by some contemporary philosophers; and I shall, I trust, make it sufficiently clear in the sequel why I am unable to accept their view.
I am not, however, concerned primarily with criticism of other theories. This paper represents an attempt to interpret a particular province of “the common moral consciousness” and to elicit the principles there implied. I begin by accepting the view that, like natural science, ethics has its data, and that it is the business of ethics to interpret these data which are the contents of the “moral consciousness.” In Section A I discuss various methods which may be used for the discovery of the relevant data, and suggest that initial enquiries can most fruitfully be pursued in the field of law and custom. In Section B I undertake an analysis of the principles of the law relating to promise-keeping. As a result of what is there found, it becomes necessary, in Section C, to discuss the nature of rights and their relation to interests, and, in Section D, the nature of duties and their relation to rights.