G. A. Cohen, answered from the texts and cited to the page.
Historical materialism is an empirical theory about the structure of society and the dynamics of history, comparable in status (though not in maturity) to nineteenth-century historical geology. Its central claims are that the productive forces — the means and methods by which humans transform nature, including labour power and the productively applied bits of science — have explanatory primacy over the relations of production in which they are deployed; that the economic base, consisting of those relations of production, explains the legal and political superstructure by way of functional explanation, the form of explanation in which an item is explained by what it tends to do for the structure that contains it; and that, across the long run of history, relations of production rise and fall according as they enable or fetter the development of the productive forces.12345
Functional explanation is a legitimate explanatory mode, structurally similar to the explanations Darwin's theory deploys, and it does not require the false-consciousness or design teleology that its critics ascribe to it. The 2000 Introduction acknowledges substantive revisions — the fettering concept's ambiguity, the limits of the strictly-material conception, the vulnerability of historical materialism to counter-examples from religion and nationalism — without abandoning the analytical- reconstructive project.
The existing level of productive power determines what relations of production would raise its level, and relations of that type consequently obtain. In other words: if production relations of type obtain at time, then that is because -type relations are suitable to the development of the forces at, given the level of their development at. Now to say that explains is not necessarily to indicate explains.Lectures on the History of Moral and Political Philosophy, p. 289
I FORCES AND RELATIONS OF PRODUCTION 1. In the first section of this chapter I present, in summary form, the interpretation of historical materialism which I offered in my book on Karl Marx's Theory of History." I define and connect the concepts of forces and relations of production, and I maintain that the basic explanations of historical materialism are functional explanations.History, Labour, and Freedom, pp. 20–21
I think these are ways of saying that the level of development of the productive forces explains the nature of the production relations, and that they in turn explain the character of the superstructure co-present with them. But what kind of explanation is ventured here? I argue that in each case what we have is a species of functional explanation. What is functional explanation?History, Labour, and Freedom, p. 25
Functional Explanation: In Marxism (i) Introduction CHAPTER IX defended functional explanation, an intellectual device indispensable to historical materialism as expounded in this book. The defence continues here. We deal with objections to a functionally construed historical materialism likely to be raised by Marxists, and by non-Marxist social scientists. Following that, various elaborations (see p.Karl Marx's Theory of History, pp. 278–279
Functional Explanation: In General (i) Introduction THE PRESENT chapter is more philosophical than any of the rest, and non-philosophical readers are likely to find it particularly difficult. Most of them will wish to proceed immediately to Chapter X, where functional explanation is discussed with greater reference to historical materialism.Karl Marx's Theory of History, pp. 249–250
KMTH established analytical Marxism as a research programme and won the Isaac Deutscher Memorial Prize; the reception in the analytical-philosophy tradition has been sustained for four decades. The principal objections come in three forms: Joshua Cohen's argument that social structures control the productive process and so cannot be explained by it (replied to in HLF Chapter 5); Jon Elster's rational-choice-Marxism case against functional explanation as failing to specify causal mechanisms (replied to in the 1982 Theory and Society paper); and the historical-fact objections about non-material drivers of social change (religion, nationalism, gender) which the strictly- material conception cannot accommodate (acknowledged and partially incorporated in HLF Chapter 8 'Restricted and Inclusive Historical Materialism'). By the late 1990s I had lost the inevitabilitarian commitments — the prediction of an immense-majority working class and the prediction of unlimited productive-force expansion had both been refuted by history — but the analytical reconstruction of historical materialism's explanatory architecture survives the empirical losses.