His immediate influence upon contemporary economists was very slight. Some of them allowed themselves to be influenced by his warmheartedness, his tenderness for the weak, and his pity for the workers, but they never found this a sufficient reason for breaking off their connections with the Classical school. Blanqui[432] in particular was a convert to the extent that he admitted some exceptions to the principle of _laissez-faire_. Theodore Fix and Droz[433] seemed won over for a moment, and Sismondi might rightly have expected that the _Revue mensuelle d’Économie politique_, started by Fix in 1833, would uphold his views. But the days of the _Revue_ were exceedingly few, and before finally disappearing it had become fully orthodox. Only one author, Buret, in his work on the sufferings of the working classes in England and France,[434] has the courage to declare himself a whole-hearted disciple of Sismondi. The name of Villeneuve-Bargemont, author of _Économie politique chrétienne_, must be added to these. His work, which was published in three volumes in 1834, bears frequent traces of Sismondi’s influence. Sismondi, though not himself a socialist, has been much read and carefully studied by socialists. It is among them that his influence is most marked. This is not very surprising, for all the critical portion of his work is really a vigorous appeal against competition and the inequalities of fortune. Louis Blanc read him and borrowed from him more than one argument against competition. The two German socialists Rodbertus and Marx are still more deeply indebted to him. Rodbertus borrowed from him his theory of crises, and owes him the suggestion that social progress benefits only the wealthier classes. Rodbertus quotes him without any mention of his name, but Marx in his _Manifesto_ has rendered him full justice, pointing out all that he owed to his penetrative analysis. The most fertile idea borrowed by Marx was that which deals with the concentration of wealth in the hands of a few powerful capitalists, which results in the increasing dependence of the working classes. This conception is the pivot of the _Manifesto_, and forms a part of the very foundation of Marxian collectivism. The other idea of exploitation does not seem to have been borrowed from Sismondi, although he might have discovered a trace of the surplus value theory in his writings. Marx endeavours to explain profit by drawing a distinction between a worker selling his labour and parting with some of his labour force. Sismondi employs terms that are almost identical, and says that the worker when selling his labour force is giving his life. Elsewhere he speaks of a demand for “labour force.” Sismondi never drew any precise conclusion from these ideas, but they may have suggested to Marx the thesis he took such pains to establish.