At that time (1844) Marx had already begun to mix among the German working classes resident in Paris, who clung to the various Socialist and Anarchist doctrines which then held sway, and he sought to influence them according to his own ideas. With Heine, too, who at that time was coquetting with Communism, he carried on a sprightly and not unfruitful intercourse. He likewise came into frequent contact with Proudhon, whom he endeavoured to make familiar with Hegelian philosophy. Already in his first work, "What is Property?" (1840) Proudhon had played with Hegelian formulae, and Marx probably believed that he could win him over to Socialism. Proudhon, who, like the German Weitling, sprang from the proletariat, ushered in his activity as a social theorist with the above-mentioned work, which had a stimulating effect on Marx and on German Socialists in general, all the more so as Proudhon manifested some acquaintance with classical German philosophy. In this book ("What is Property?" German edition, 1844, p. 289) he sums up the whole matter as follows: "Expressing this according to the Hegelian formula, I should say that Communism, the first kind, the first determination of social life, is the first link in social evolution, the _thesis_; property is the antagonistic principle, the _antithesis_; if only we can get the third factor, the _synthesis_, the question is solved. This synthesis comes about only through the cancelling of the thesis by the antithesis; one must therefore in the last instance examine its characteristics, discard what is anti-social, and in the union of the remaining two is then seen the real kind of human social life." That was indeed a superficial conception of Hegelian dialectics, for what Proudhon wanted to find was not a synthesis but a combination; still for a French working man it was a smart performance to have manipulated German philosophical formulae, and would justify the most sanguine hopes. Marx did not want to let this opportunity slip, and in "debates both late and long" he discussed Hegelian philosophy with Proudhon.--(Marx: "The Poverty of Philosophy," German edition, Stuttgart, 1885, p. 29.) In the midst of this activity, however, Marx and other German contributors to the Paris _Vorwaerts_ were expelled from France in January, 1845, at the instigation of the Prussian Government. Marx packed up his traps and left for Brussels, where he lived, with short interruptions, until the outbreak of the European Revolution in February, 1848. During his sojourn in Brussels his time was occupied mainly with economic studies, for which Engels placed his library of works on political economy at his disposal. Marx embodied the result of these studies in the criticism directed against Proudhon in his "Misere de la Philosophie" (Poverty of Philosophy), published in 1847. IV. CONTROVERSY WITH PROUDHON.