The concept of totality
Though in this text the authors only infrequently use the term “totality” (which appears much more often in the later Marx and, if anything, a little too often in the writing of later Marxists), it is nonetheless one of the core, structuring concepts of The German Ideology. Perhaps the most important thing that Marx and Engels believe sets their form of thought apart from all of their peers and predecessors is the capacity of their analysis to grasp historical and contemporary reality as an organic, dynamic whole. Rather than proceeding by isolating one particular area of society—philosophy, the development of industry, conquest, religion, war, and so on—and seeking to discover its “effects,” they believe that our laws, behaviors, social and political realms, and ideologies are meaningful only when seen within the total socio-economic structure in which they operate. In other words, the parts are comprehensible as parts only when analyzed with reference to the whole. Human reality isn’t an assemblage of atomized parts, or individuals. It isn’t some sort of sprawling Lego construction that you can understand by disassembling it to see how all the pieces fit together. It’s a dynamic, ongoing process, constantly being made and remade, comprehensible only from the inside, where we—us humans that is—do in fact live.
Ideology and material conditions
Though they devote the vast majority of their attention and emphasis to the fundamental role of material conditions, the development of industry, the mode of production, and the division of labor on the rest of human life, Marx and Engels’s theory doesn’t, in the last analysis, see “economic” activity as somehow more important, more fundamental, or determinative of everything else. However, it is true that they do occasionally, often in more polemical passages aimed at the fervently idealist Young Hegelians, appear to dismiss “ideology,” philosophy, and perhaps culture in general as more or less a byproduct of the real business of material production.
Additionally, it's crucial to understand that the term “ideology,” just as it does generally, is used in several different, though connected, ways within The German Ideology. Roughly speaking, it has two crucial, distinct meanings: 1) Ideology as a consciously formulated system of thought, which at least attempts to achieve internal consistency, such as the philosophy of the Young Hegelians. 2) Ideology as a more or less invisible array of common-sense ideas through which one understands reality, a way of approaching the world that makes it comprehensible as a structure, as meaningful. It hardly makes sense to call these ideas “beliefs,” as it almost never occurs to us to doubt them. The distinction between these two senses of ideology is what Marx is getting at when he describes the divisions between the ruling class, who certainly “believe” their own dominant ideology, and their dedicated “ideologists.” Marx and Engels analyze both of these “forms” of ideology in this work, first outlining how these “ideologists,” as the division of mental and physical labor develops, come to live in a world in which it’s possible to believe that they can engage in “pure” thought, unsullied by the messy business of, for example, producing the food they eat or the desks at which they sit. But for the capitalists as well, their commitment to the dominant ideology (which, as the dominant class, is theirs) is not simply a matter of vulgar self-interest. They “believe” this ideology—their consciousness is structured by it—because they live it, because playing by its rules—perpetual competition, suppressing wages, accumulating capital and thus expanding their ability to command the labor of others—works. One thing many readers of Marx overlook is that he understands this fact; namely, that in a capitalist society capitalists serve an absolutely vital role, without which the entire system ceases to function.
(Proletarian) revolution
Throughout The German Ideology, Marx and Engels consider and dismiss a variety of different candidates for the driving force of historical change before presenting their argument that this role properly belongs to revolution. Their conception of revolution is, crucially, a revolution that fundamentally alters actual material conditions, such as the mode of production and division of labor, and grows out of pre-existing contradictions, specifically between the relations and forces of production, and possibilities within those conditions. Thus the bourgeois revolution that replaces the feudal order depends on the growing power of the bourgeois class due to the increasingly significant role of commerce within the context of colonialism, as well as the development of money and the dependence of the modern state on credit extended by capitalists. What makes the proletarian revolution they call for different is that instead of simply altering the division of labor it will abolish it entirely. Furthermore, within the communist society established in the wake of the proletarian revolution, human beings will for the first time subject the development of the forces of production to conscious social control. Since the relations of production (the organization of society) will then direct the development of the forces of production, these aspects of human civilization will no longer come into contradiction and produce the need for further revolutions.
The division of labor
The division of labor is one of the central elements of Marx’s analysis in The German Ideology, and much of the text is devoted to tracing its development throughout history. Marx’s conception of the division of labor also differs in two crucial ways from its other most famous modern elaboration, Emile Durkheim’s Division of Labor in Society. Firstly, Marx sees the division of labor as existing both as a universal feature of all forms of human social organization and, in its most developed form, a specific characteristic of capitalist society. This is because, under capitalism, the division of labor becomes an accidental feature, rather than a “natural” one, of human life, since the need for a class of pin-head-makers is under capitalism necessary only for the needs of capital, i.e., profit, rather than fundamentally necessary for the reproduction of human life. Secondly, while Marx acknowledges the role of the division of labor in expanding the productive capacities of humanity as a whole and bringing, eventually, all of humanity into real, material relations of interdependence (which he sees as positive), he also views it as a source of oppression that needs to be abolished.