Williams, Gavin. "Imperialism and Development: A Critique." World Development 6, no. 7–8 (1978): 925–36.

At a certain stage of their development, the material productive forces of society come in conflict with the existing relations of production … From forms of the development of the productive forces these relations turn into their fetters. Then begins an epoch of social revolution. …No social order ever perishes before all productive forces for which there is room in it have developed; and new, higher relations of production never appear before the materials conditions of their existence have matured in the womb of the old society itself. Therefore mankind always sets itself such tasks as it can solve; since, looking at the matter more closely, it will always be found that the tasks itself arises omly when the material conditions for its solution exist or least are in the process of formation. K. Marx, Preface to A Contribution to the Critique of Political Economy.

The transformation, through the division of labour, of personal power (relationships) into material powers, cannot be dispelled by dismissig the general idea of it from one's mind, but can only be abolished by the individuals again subjecting those material powers to themselves community (with others has each) individual the means of cultivating his gifts in all directions; only in the community, therefore, is personal freedom possible. In the previous substitutes for the community. in the State, etc. personal freedom has existed only for the individuals who developed within the relationships of the ruling class, and only in so far as they were individuals of this class. The illusory community, in which individuals have up till now combined, always took on an independent existence in relation to them, and was at the same time, since it was the combination of one class over another, not only a completely illusory community, but a new fetter as well. In the real community the individuals obtain their freedom in and through their association. K. Marx & F. Engels,The German Ideology.