I read [Vollmar's] second article rather hurriedly, with two or three people talking the whole time. Otherwise the way he represents the French Revolution to himself would have led me to detect the French influence and with it my Vollmar too, no doubt. You have perceived this side quite correctly. He at last is the dreamed-of realisation of the phrase about the "one reactionary mass." All the official parties united in one lump here, all the Socialists in one column there--great decisive battle. Victory all along the line at one blow. In real life things do not happen so simply. In real life, as you also remark, the revolution begins the other way round by the great majority of the people and also of the official parties massing themselves together against the government, which is thereby isolated, and overthrowing it; and it is only after those of the official parties whose existence is still possible have mutually and successively accomplished one another's destruction that Vollmar's great division takes place and with it the prospect of our rule. If, like Vollmar, we wanted to start straight off with the final act of the revolution we should be in a miserably bad way. In France the long expected split has taken place. The original conjunction of Guesde and Lafargue with Malon and Brousse was no doubt unavoidable when the party was founded, but Marx and I never had any illusions that it could last. The issue is purely one of principle: is the struggle to be conducted as a class struggle of the proletariat against the bourgeoisie, or is it to be permitted that in good opportunist (or as it is called in the Socialist translation: possibilist) style the class character of the movement, together with the programme, are everywhere to be dropped where there is a chance of winning more votes, more adherents, by this means. Malon and Brousse, by declaring themselves in favour of the latter alternative, have sacrificed the proletarian class character of the movement and made separation inevitable. All the better. The development of the proletariat proceeds everywhere amidst internal struggles and France, which is now forming a workers' party for the first time, is no exception. We in Germany have got beyond the first phase of the internal struggle, other phases still lie before us. Unity is quite a good thing so long as it is possible, but there are things which stand higher than unity. And when, like Marx and myself, one has fought harder all one's life long against the alleged Socialists than against anyone else (for we only regarded the bourgeoisie as a class and hardly ever involved ourselves in conflicts with individual bourgeois), one cannot greatly grieve that the inevitable struggle has broken out. ... I hope this will reach you before they put you behind the bars. Hearty greetings from Marx and Tussy. Marx is rapidly recovering and if his pleurisy does not come back he will be stronger next autumn than he has been for years. If you see Liebknecht in the K figturm  (as they say in Berne), give him the best regards from all of us.
Letters: Marx-Engels Correspondence 1882