The first lecture, "The Theory of Corruption in Roman History," sums up the fundamental idea of my conception of the history of Rome. The essential phenomenon upon which all the political, social, and moral crises of Rome depend is the transformation of customs produced by the augmentation of wealth, of expenditure, and of needs,--a phenomenon, therefore, of psychological order, and one common in contemporary life. This lecture should show that my work does not belong among those written after the method of economic materialism, for I hold that the fundamental force in history is psychologic and not economic. The three following lectures, "The History and Legend of Antony and Cleopatra," "The Development of Gaul," and "Nero," seem to concern themselves with very different subjects. On the contrary, they present three different aspects of the one, identical problem--the struggle between the Occident and the Orient--a problem that Rome succeeded in solving as no European civilisation has since been able to do, making the countries of the Mediterranean Basin share a common life, in peace. How Rome succeeded in accomplishing this union of Orient and Occident is one of the points of greatest interest in its history. The first of these three lectures, "Antony and Cleopatra," shows how Rome repulsed the last offensive movement of the Orient against the Occident; the second, "The Development of Gaul," shows the establishing of equilibrium between the two parts of the Empire; the third, "Nero," shows how the Orient, beaten upon fields of battle and in diplomatic action, took its revenge in the domain of Roman ideas, morals, and social life. The fifth lecture, "Julia and Tiberius," illustrates, by one of the most tragic episodes of Roman history, the terrible struggle between Roman ideals and habits and those of the Græco-Asiatic civilisation. The sixth lecture, "The Development of the Empire," summarises in a few pages views to be developed in detail in that part of my work yet to be written. I have said that not all history can be explained by economic forces and factors, but this does not prevent me from regarding economic phenomena as also of high importance. The seventh lecture, "Wine in Roman History," is an essay after the plan in accordance with which, it seems to me, economic phenomena should be treated.