The title of this book may not unnaturally provoke suspicion. After all, howsoever we define it, socialism is a modern thing, and dependent almost wholly on modern conditions. It is an economic theory which has been evolved under pressure of circumstances which are admittedly of no very long standing. How then, it may be asked, is it possible to find any real correspondence between theories of old time and those which have grown out of present-day conditions of life? Surely whatever analogy may be drawn between them must be based on likenesses which cannot be more than superficial. The point of view implied in this question is being increasingly adopted by all scientific students of social and political opinions, and is most certainly correct. Speculation that is purely philosophic may indeed turn round upon itself. The views of Grecian metaphysicians may continue for ever to find enthusiastic adherents; though even here, in the realm of purely abstract reasoning, the progressive development of science, of psychology, and kindred branches of knowledge cannot fail by its influence to modify the form and arrangement of thought. But in those purely positive sciences (if indeed sciences they can properly be called) which deal with the life of man and its organisation, the very principles and postulates will be found to need continual readjustment. For with man's life, social, political, economic, we are in contact with forces which are of necessity always in a state of flux. For example, the predominance of agriculture, or of manufacture, or of commerce in the life of the social group must materially alter the attitude of the statesman who is responsible for its fortunes; and the progress of the nation from one to another stage of her development often entails (by altering from one class to another the dominant position of power) the complete reversal of her traditional maxims of government. Human life is not static, but dynamic. Hence the theories weaved round it must themselves be subject to the law of continuous development.