This is the second in a series on the history of dialectical philosophy.

Like everything else, communist dialectical philosophy did not simply jump into existence. Its development has been a long process involving many theoretical struggles. These struggles have always been connected to practical political and economic issues. Getting a thorough understanding of dialectics in the 21st century requires knowing something about the process that got us here. This means that we have to study both the milestones and the mistakes in the development of dialectics within the communist movement. That is the purpose of this series.
In the first column in the series, we surveyed profound ideas from dialectical theory before Marx, ideas from Heraclitus and from Hegel. In this column and the next we discuss ideas from Karl Marx, the founder of communist dialectics. Karl Marx once wrote that he intended to produce a compact summary of his views about dialectics, but he never got around to it. Instead he applied his dialectical approach to many topics in his book Capital and in his political writings. These are our sources for Marx's dialectics and they are good sources, since they show what dialectics can be used for.

Dialectical Contradiction
Marx wrote that dialectical contradictions (which he called "Hegelian") are the "source of all dialectics." His examples show that a contradiction consists of two connected opposites that struggle and interfere with each other. For example, Marx described the contradictory relation between the use value and exchange value of a commodity (what you use it for vs. what you pay for it) as two "mutually conditioning, inseparable moments, which belong to one another, but which are at the same time extremes which exclude or oppose one another." In capitalism, no matter how hungry you are, if you don't have the cash, you don't eat. Here the two sides of the contradiction are called "moments," and the kind of connection they have is called "mutually conditioning." That means that each side makes the other side different, like the two sides of the relation between parents and children.
Not all opposites contradict each other all the time. For example, circulation of goods and services that workers need stands in opposition to the circulation of money and credit in a capitalist economy. Much of the time money and credit make the circulation of goods easier. In an economic crisis, however, debts and the need for money to pay them get in the way of the circulation of commodities and freeze up the economy. Then the two opposites, goods and services vs money and credit, struggle with each other. That is what makes their opposite relationship a contradiction.

Other Contradictions of Capitalism
Marx identified many contradictions within capitalism, including those that lead to "explosions, cataclysms, crises, … regularly occurring catastrophes … [and] finally to its violent overthrow." One tendency in capitalism is to increase the forces of production without limit. This tendency exists because competition drives each capitalist to produce more goods at a lower cost. Under capitalism, however, things will only be produced if they can be sold for a profit.
When capitalists try to find buyers for their production, they come up against a contradictory opposite. A large part of capitalism's output is sold to workers who must be able to afford the product. But to make profits in production, capitalists need to hold down the wages of workers. The capitalists' need to expand production and sell it to workers, and their need to hold down workers' wages contradict each other.
Marx calls this contradiction the fundamental contradiction of capitalism. It is an example of a general pattern of the contradiction between capitalism's fundamental relations of ownership and control, and the development of the forces of production. This contradiction means that although capitalism has created tremendous productive forces, the things the bosses need to do to make maximum profits interfere with the fullest growth of production to meet people's needs.

Resolution of Contradictions
It is a basic idea of dialectics that when a contradiction exists and its two opposite sides struggle, the contradiction tends to move toward its own elimination. The process of elimination of a contradiction is called resolution. Marx wrote that the contradiction between the workers as a class and the capitalists as a class "is private property as its developed relation of contradiction, hence an energetic relation driving toward resolution." In a capitalist crisis, the contradiction between the use of money and the circulation of goods is eventually resolved—until the next crisis. The fundamental contradiction between expanding production and holding down wages can't be resolved under capitalism, however, but only by communist revolution.
In our next column, we will discuss Marx's ideas on how contradictions can be resolved.