Four able and penetrating writers have recently given us their considered views on the nature and scope of international relations as a branch of higher learning.* While each of them starts from a somewhat different intellectual viewpoint, they display a striking similarity of conception of the general place of international relations (hereafter referred to as IR) in the spectrum of human knowledge. I propose here, not to subject these writings to critical scrutiny, but to use them as a starting point for a brief inspection of the scope of international relations as it now seems to be taking form in the work of the leading scholars in the field.

It is necessary to note in the beginning that “scope” is a dangerously ambiguous word. It suggests that the subject matter under inquiry has clearly discernible limits, and that all one has to do in defining its scope is to trace out these boundaries in much the manner of a surveyor marking out the bounds of a piece of real property. Actually, it is nothing of the sort. A field of knowledge does not possess a fixed extension in space but is a constantly changing focus of data and methods that happen at the moment to be useful in answering an identifiable set of questions. It presents at any given time different aspects to different observers, depending on their point of view and purpose. The boundaries that supposedly divide one field of knowledge from another are not fixed walls between separate cells of truth but are convenient devices for arranging known facts and methods in manageable segments for instruction and practice. But the foci of interest are constantly shifting and these divisions tend to change with them, although more slowly because mental habits alter slowly and the vested interests of the intellectual world are as resistant to change as those of the social world.