The reader of this work will miss something which he has been accustomed to find in books on Socialism. Professor Sombart has not given us synopses of the theories of St. Simon, Proudhon, Marx, Owen, and others. His work marks the coming of a period in which socialism is to be studied, rather than the speculations of socialists. Theories and plans no longer constitute the movement. There are still schools of socialistic thought; but there is something actually taking place in the industrial world that is the important part of the socialistic movement. Reality is the essence of it. The structure of the world of industry is changing. Great establishments are exterminating small ones, and are forming federations with each other. Machinery is producing nearly every kind of goods, and there is no longer a place in the world for such a middle class as was represented by the master workman, with his slowly learned handicraft and his modest shop. These facts construed in a certain way are the material of socialism. If we see in them the dawn of an era of state industry that shall sweep competition and competitors out of the field, we are evolutionary socialists. We may need a doctrinal basis for our view of the evolution that is going on; and we may find it in the works of Marx and others; but already we have ceased to have an absorbing interest in the contrasts and the resemblances that their several theories present. We have something to study that is more directly important than doctrinal history. In Professor Sombart's study, Owenism, indeed, has an important place, since the striking element in it is something that the present movement has completely put away, namely, utopianism. No one now thinks, as did Owen, that merely perceiving the beauty of the socialistic ideal is enough to make men fashion society after that pattern. No one thinks that society can be arbitrarily shaped after any pattern. Marxism, in practice, means realism and a reliance on evolution, however little the wilder utterances of Marx himself may suggest that fact. Internationalism is also a trait of this modern movement; but it is not of the kind that is represented by the International Working-Men's Association. It is a natural affiliation of men of all nations having common ends to gain. The relation of a thinker to a practical movement cannot lose its importance. It is this connection that Professor Sombart gives us, and his work is an early representative of the coming type of books on Socialism. It treats of realities, and of thought that connects itself with realities. It treats, indeed, of a purposeful movement to assist evolution, and to help to put the world into the shape that socialistic theorists have defined. Here lies the importance of the study of theory.