The bourgeoisie destroyed the feudal conditions of property; the proletariat will put an end to the bourgeois conditions of property. Between the proletariat and the bourgeoisie a struggle, an implacable war, a war to the knife, is as inevitable as, was in its way, the struggle between the bourgeoisie and the privileged estates. _But every class war is a political war._ In order to do away with feudal society the bourgeoisie had to seize upon political power. In order to do away with capitalist society the proletariat must do the same. Its political task is therefore traced out for it beforehand by the force of events themselves, and not by any abstract consideration. It is a remarkable fact that it is only since Karl Marx that Socialism has taken its stand upon the class war. The Utopian Socialists had no notion--even an inexact one--of it. And in this they lagged behind their contemporary theorists of the bourgeoisie, who understood very well the historical significance at any rate of the struggle of the third estate against the nobles. If every "new conception" of human nature seemed to supply very definite indications as to the organisation of "the society of the future," Scientific Socialism is very chary of such speculations. The structure of society depends upon the conditions of its productive forces. What these conditions will be when the proletariat is in power we do not know. We now know but one thing--that the productive forces already at the disposal of civilised humanity imperatively demand the socialisation and systematised organisation of the means of production. This is enough to prevent our being led astray in our struggle against "the reactionary mass." "The Communists, therefore, are practically the most advanced and resolute section of the working class parties of every country ... theoretically they have over the great mass of the proletariat the advantage of clearly understanding the line of march, the conditions, and the ultimate general results of the proletarian movement."[5] These words, written in 1848, are to-day incorrect only in one sense: they speak of "working class parties" independent of the Communist party; there is to-day no working class party which does not more or less closely follow the flag of Scientific Socialism, or, as it was called in the Manifesto, "Communism." Once again, then, the point of view of the Utopian Socialists, as indeed of all social science of their time, was human nature, or some abstract principle deriving from this idea. The point of view of the social science, of the Socialism of our time is that of economic reality, and of the immanent laws of its evolution.