It is but recently that, in pure theory, the concept of social value came into prominence. The founders of what is usually called the modern system of theory, as distinguished from the classical, never spoke of social, but only of individual value. Recently, however, the former concept has been introduced by some leaders of economic thought, and has quickly met with general approval. To-day it is to be found in nearly every text-book. Since it is generally used without careful definition, some interest attaches to a discussion of its meaning and its role; and it is the purpose of this paper to contribute to such a discussion. The reader is asked to bear in mind, first, that our question is a purely methodological one and has nothing whatever to do with the great problems of individualism and collectivism; further, that we shall consider the question for the purposes of pure theory only; and, finally, that we confine our inquiry to the concept of social value without including several other concepts which also have social aspects.