The following treatise is an expansion, under a new title, of one originally published (1900) under the name of _An Introduction to English Politics_. Several friendly reviewers of that work objected, not unjustly, that its title was something of a misnomer, or at least an imperfect indication of its contents. It had, as a matter of fact, originated remotely in a lecture delivered as preliminary to a course on "Modern English Politicians" (from Bolingbroke to Gladstone), the aim of the prefatory address being to trace in older politics, home and foreign, general laws which should partly serve as guides to modern cases, or at least as preparation for their scientific study; while the main course dealt with modern political problems as they have arisen in the careers and been handled by the measures of modern English statesmen. It was that opening exposition, developed into an essay, and published as a series of magazine articles, that had been further expanded into this treatise, by way of covering the ground more usefully; and the original name is therefore retained as a sub-title. It is perhaps unnecessary to explain that the book makes no pretension to being a complete or systematic treatment of political history, or of political forms and theories. The object in view from the first has been, not the technical anatomy or documentary history of institutions, but the bringing into light of the ruling forces in all political life, ancient and modern alike. It seeks to help the reader to fulfil the precept of Montaigne: "_Qu'il ne luy apprenne pas tant les histoires qu'à en juger._" Since it was first written, there has been so much fresh sociological study of history that I need not repeat the justification originally offered for my undertaking. Alike as to ancient and modern history, the effort of scholars is now more and more towards comprehension of historic causation in terms of determining conditions, the economic above all; so much so that I have profited somewhat in my revision from various recent works, and might with more leisure have done so more fully. Revised as it is, however, the book may serve to expound views of history which are still not generally accepted, and to call in question fallacious formulas which seem to me still unduly common.