This vast study did, indeed, throw great light, not only upon poverty in London, but upon human nature in general. On the other hand, it raised more questions than it settled and, if it demonstrated anything, it was the necessity, as Booth suggests, for a restatement of the problem. Sociology seems now, however, in a way to become, in some fashion or other, an experimental science. It will become so as soon as it can state existing problems in such a way that the results in one case will demonstrate what can and should be done in another. Experiments are going on in every field of social life, in industry, in politics, and in religion. In all these fields men are guided by some implicit or explicit theory of the situation, but this theory is not often stated in the form of a hypothesis and subjected to a test of the negative instances. We have, if it is permitted to make a distinction between them, investigation rather than research. What, then, in the sense in which the expression is here used, is social research? A classification of problems will be a sort of first aid in the search for an answer. 1. _Classification of social problems._--Every society and every social group, _capable of consistent action_, may be regarded as an organization of the wishes of its members. This means that society rests on, and embodies, the appetites and natural desires of the individual man; but it implies, also, that wishes, in becoming _organized_, are necessarily disciplined and controlled in the interest of the group as a whole. Every such society or social group, even the most ephemeral, will ordinarily have (a) some relatively formal method of defining its aim and formulating its policies, making them explicit, and (b) some machinery, functionary, or other arrangement for realizing its aim and carrying its policies into effect. Even in the family there is government, and this involves something that corresponds to legislation, adjudication, and administration. Social groups, however, maintain their organizations, agencies, and all formal methods of behavior on a basis and in a setting of instinct, of habit, and of tradition which we call human nature. Every social group has, or tends to have, its own culture, what Sumner calls "folkways," and this culture, imposing its patterns upon the natural man, gives him that particular individuality which characterizes the members of groups. Not races merely but nationalities and classes have marks, manners, and patterns of life by which we infallibly recognize and classify them. Social problems may be conveniently classified with reference to these three aspects of group life, that is to say, problems of (a) organization and administration, (b) policy and polity (legislation), and (c) human nature (culture).