tionary political movements, and working-class methods of action.
Both he and Engels penetrated into every nest of discontent. They came
personally in touch with every group of dissidents. They spent many
weary but invaluable weeks in the greatest libraries of Europe, with the
result that they became thoroughly schooled in philosophy, economics,
science, and languages. They pursued, to the minutest detail, with an
inexhaustible thirst, the theories not only of the "authorities" but
also of nearly every obscure socialist, radical, and revolutionist in
England, France, Russia, and Germany.

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, an