In Brussels, Paris, and London, around the forties, a number of brilliant minds seemed somehow or other to come frequently in contact with each other. Many of them had been driven out of their own countries, and, as exiles abroad, they had ample leisure to plan their great conspiracies or to debate their great theories. Some of the notable radicals of the period were Heine, Freiligrath, Herwegh, Willich, Kinkel, Weitling, Bakounin, Ruge, Ledru-Rollin, Blanc, Blanqui, Cabet, Proudhon, Ernest Jones, Eccarius, Marx, Engels, and Liebknecht; and many of them came together from time to time and, in great excitement and passion, fought as "Roman to Roman" over their panaceas. Marx and Engels knew most of them and spent innumerable hours, not infrequently entire days and nights, at a sitting, in their intellectual battles. It was a most fortunate thing for Marx that the French Government should have driven him in 1849 to London. "Capital" might never have been written had he not been forced to study for a long period the first land in all Europe in which modern capitalism had obtained a footing. On his earlier visit in 1845 he had spent a few weeks with Engels in the great factory centers, and he had been deeply impressed with this new industrialism and no less, of course, with the English labor movement. Nothing to compare with it then existed in France or Germany. As early as 1840 many of the trades were well organized, and repeated efforts had been made to bring them together into a national federation. How thoroughly Engels knew this movement and its varied struggles to better the status of labor is shown in his book, "The Condition of the Working Class in England in 1844." How thoroughly and fundamentally Marx later came to know not only the actual working-class movement, but every economic theory from Adam Smith to John Stuart Mill, and every insurgent economist and political theorist from William Godwin to Bronterre O'Brien, is shown in "Capital." In fact, not a single phase of insurgent thought seemed to escape Marx and Engels, nor any trace of revolt against the existing order, whether political or industrial. In Germany they were schooled in philosophy and science; in France they found themselves in a most amazing fermentation of revolutionary spirit and idealism; and in England they studied with the minutest care the cooeperative movement and self-help, the trade-union movement with its purely economic aims and methods, the Chartist movement with its political action, and the Owenite movement, both in its purely utopian phases and in its later development into syndicalist socialism. This long and profound study placed Marx and Engels in a position infinitely beyond that of their contemporaries. Possessed as they were of unusual mental powers, it was inevitable that such a training should have placed them in a position of intellectual leadership in the then rapidly forming working-class organizations of Europe.