Durkheim is sometimes referred to, in comparison with other contemporary sociologists, as a realist. This is a reference to the controversy of the medieval philosophers in regard to the nature of concepts. Those who thought a concept a mere class-name applied to a group of objects because of some common characteristics were called nominalists. Those who thought the concept was _real_, and not the name of a mere collection of individuals, were realists. In this sense Tarde and Giddings and all those writers who think of society as a collection of actually or potentially _like-minded_ persons would be nominalists, while other writers like Simmel, Ratzenhofer, and Small, who think of society in terms of interaction and social process may be called realists. They are realist, at any rate, in so far as they think of the members of a society as bound together in a system of mutual influences which has sufficient character to be described as a process. Naturally this process cannot be conceived of in terms of space or physical proximity alone. Social contacts and social forces are of a subtler sort but not less real than physical. We know, for example, that vocations are largely determined by personal competition; that the solidarity of what Sumner calls the "in" or "we" group is largely determined by its conflict with the "out" or "other" groups. We know, also, that the status and social position of any individual inside any social group is determined by his relation to all other members of that group and eventually of all other groups. These are illustrations of what is meant concretely by social interaction and social process and it is considerations of this kind which seem to justify certain writers in thinking of individual persons as "parts" and of society as a "whole" in some other sense than that in which a dust heap is a whole of which the individual particles are parts. Society not only continues to exist _by_ transmission, _by_ communication, but it may fairly be said to exist _in_ transmission, _in_ communication. There is more than a verbal tie between the words common, community, and communication.[39] Communication, if not identical with, is at least a form of, what has been referred to here as social interaction. But communication as Dewey has defined the term, is something more and different than what Tarde calls "inter-stimulation." Communication is a process by which we "transmit" an experience from an individual to another but it is also a process by which these same individuals get a common experience.