The materialist theory of history denies that art can in itself change the course of history; but it insists that art can be an active element in such change. Indeed, when Marx came to consider the relation between base and superstructure, it was art which he selected as an instance of the complexity and indirectness of that relationship:
In the case of the arts, it is well known that certain periods of their flowering are out of all proportion to the general development of society, hence also to the material foundation, the skeletal structure, as it were, of its organisation. For example, the Greeks compared to the moderns or also Shakespeare. It is even recognised that certain forms of art, e.g. the epic, can no longer be produced in their world epoch-making, classical stature as soon as the production of art, as such, begins; that is, that certain significant forms within the realm of the arts are possible only at an undeveloped stage of artistic development. If this is the case with the relation between different kinds of art within the realm of art, it is already less puzzling that it is the case in the relation of the entire realm to the general development of society. The difficulty consists only in the general formulation of these contradictions. As soon as they have been specified, they are already clarified.
Marx is considering here what he calls ‘the unequal relationship of the development of material production... to artistic production’. It does not follow that the greatest artistic achievements depend upon the highest development of the productive forces, as the example of the Greeks, who produced major art in an economically undeveloped society, clearly evidences. Certain major artistic forms like the epic are only possible in an undeveloped society. Why then, Marx goes on to ask, do we still respond to such forms, given our historical distance from them?:
But the difficulty lies not in understanding that the Greek arts and epic are bound up with certain forms of social development. The difficulty is that they still afford us artistic pleasure and that in a certain respect they count as a norm and as an unattainable model.
Why does Greek art still give us aesthetic pleasure? The answer which Marx goes on to provide has been universally lambasted by unsympathetic commentators as lamely inept:
A man cannot become a child again, or he becomes childish. But does he not find joy in the child’s naivete, and must he himself not strive to reproduce its truth at a higher stage? Does not the true character of each epoch come alive in the nature of its children? Why should not the historic childhood of humanity, its most beautiful unfolding, as a stage never to return, exercise an eternal charm? There are unruly children and precocious children. Many of the old peoples belong in this category. The Greeks were normal children. The charm of their art for us is not in contradiction to the undeveloped stage of society on which it grew. (It) is its result, rather, and is inextricably bound up, rather, with the fact that the unripe social conditions under which it arose, and could alone rise, can never return.
So our liking for Greek art is a nostalgic lapse back into childhood – a piece of unmaterialist sentimentalism which hostile critics have gladly pounced on. But the passage can only be treated thus if it is rudely ripped from the context to which it belongs – the draft manuscripts of 1857, known today as the Grundrisse. Once returned to that context, the meaning becomes instantly apparent. The Greeks, Marx is arguing, were able to produce major art not in spite of but because of the undeveloped state of their society. In ancient societies, which have not yet undergone the fragmenting ‘division of labour’ known to capitalism, the overwhelming of ‘quality’ by ‘quantity’ which results from commodity-production and the restless, continual development of the productive forces, a certain ‘measure’ or harmony can be achieved between man and Nature – a harmony precisely dependent upon the limited nature of Greek society. The ‘childlike’ world of the Greeks is attractive because it thrives within certain measured limits – measures and limits which are brutally overridden by bourgeois society in its limitless demand to produce and consume. Historically, it is essential that this constricted society should be broken up as the productive forces expand beyond its frontiers; but when Marx speaks of ‘striv(ing) to reproduce its truth at a higher stage’, he is clearly speaking of the communist society of the future, where unlimited resources will serve an unlimitedly developing man.
 Introduction to the Grundrisse.