ACCORDING TO the German socialist and philosopher Karl Vörlander writing in the early twentieth century, “The moment anyone started to talk to Marx about morality, he would roar with laughter.”

I don’t know whether Vörlander’s story is true, but there is certainly plenty to laugh about when our rulers talk about morality. Almost invariably they use it as a way of promoting their own interests, pretending they are acting for the common good or for the benefit of humanity.

But it is hard to believe that morality is nothing more than ruling-class ideology. Most people become socialists because they think that some things should be opposed not just because they threaten their own material interests, but because they think they are wrong in and of themselves—racism and sexism, imperialist wars that kill hundreds of thousands of people, a system that destroys people’s lives in order to make a tiny number of people fantastically rich.

Where, though, do our ideas of morality come from? As a materialist, Marx rejected the idea that moral rules have a divine source and are imposed on human society from the outside. But he also rejected the idea, defended by the eighteenth-century German philosopher Immanuel Kant, that morality had a purely rational basis.

Kant argued that moral rules had to apply equally to all rational agents. He thought that it followed from this that some rules could be shown to be valid and others invalid. A valid rule is one that you would consistently wish that everyone would follow, and an invalid rule one that you would not consistently wish to be universalized. So Kant held that lying was morally wrong, because if everyone lied when it was to their advantage to do so, trust and communication would be undermined and your own goals would be frustrated.

But in the early nineteenth century Hegel argued that Kantian morality was all form and no content—or, rather, that the content was smuggled in from elsewhere. For instance, Kant believed that theft was wrong, because if everyone stole it would undermine the institution of private property. This, though, leaves open the question of why we should have private property in the first place. Hegel’s response was that the content of morality comes from cultural and historical traditions. But while this is true in a descriptive sense, it tells us nothing about if and when those traditions should be accepted or rejected.

The most influential moral theories since the eighteenth century have tended to see morality as a necessary way of holding human impulses in check. A central component of Kant’s theory, for instance, is that morality has to control human desires in order to prevent social conflict.

Underlying these views is the assumption that human beings are competitive individuals who seek their own self-interest and who will engage in a war of all against all if left to their own devices. Morality is supposed to moderate the war so that society can hold together.

IN HIS Economic and Philosophical Manuscripts of 1844 and elsewhere, Marx starts with a very different understanding of human nature. In this conception, we are not naturally competitive, rather, we are social creatures who cannot survive without cooperating with each other. Modern science confirms this view. Humans did not evolve as a collection of atomized individuals constantly at war with one another, but in social groups that depended on mutual support. According to the anthropologist Richard Lee:

Before the rise of the state and the entrenchment of social inequality [about 5,000 years ago], people lived for millennia in small-scale kin-based social groups, in which the core institutions of economic life included collective or common ownership of land and resources, generalized reciprocity in the distribution of food, and relatively egalitarian political relations.

The idea that violence and war have always been part of human society may seem like common sense. But an examination of the historical evidence reveals a very different picture. As the anthropologist R. Brian Ferguson points out, “the global archaeological record contradicts the idea that war was always a feature of human existence; instead, the record shows that warfare is largely a development of the past 10,000 years.”

Warfare became a feature of human society only as a consequence of specific historical developments—crucially the establishment of permanent settlements with accumulated wealth, and the emergence of “social hierarchy, an elite, perhaps with its own interests and rivalries.” Rather than war being the expression of some general human propensity towards violence, it reflects the interests of those at the top of society who are most likely to benefit from it.

Evidence of this kind supports the view that human beings are not naturally violent, selfish, competitive, greedy, or xenophobic, it is not natural for human societies to be organized hierarchically or for women to have lower social status than men, and capitalism does not exist because it uniquely reflects human nature, as its defenders often claim.

Marx recognized that in different social and historical circumstances, human behavior and psychology can vary dramatically, just as in different physical circumstances water can be a solid, a liquid, or a gas. As he put it, “the human essence is no abstraction inherent in each single individual. In its reality it is the ensemble of the social relations.”

Nevertheless, the range of potential human behaviors has limits, ultimately rooted in human biology and psychology. If such limits did not exist, then it would be possible for there to be class societies in which the majority of the population was socially conditioned to accept its exploitation and oppression. But the whole history of class societies is a refutation of that idea.

No one was more aware of this than Marx, which is why from his earliest writings he condemns capitalism as inhumane—a society in which most human beings cannot live satisfying lives, engage in fulfilling work, or relate in satisfactory ways to other people or to the rest of the natural world. In other words, capitalism frustrates basic human needs and human nature. In capitalist society,

labor is external to the worker, i.e. it does not belong to his essential being; … in his work, therefore, he does not affirm himself but denies himself, does not feel content but unhappy, does not develop freely his physical and mental energy but mortifies his body and ruins his mind. The worker therefore only feels himself outside his work, and in his work feels outside himself. He is at home when he is not working, and when he is working he is not at home. His labor is therefore not voluntary, but coerced; it is forced labor. It is therefore not the satisfaction of a need; it is merely a means to satisfy needs external to it. Its alien character emerges clearly in the fact that as soon as no physical or other compulsion exists, labor is shunned like the plague…. As a result, therefore, man (the worker) no longer feels himself to be freely active in any but his animal functions—eating, drinking, procreating, or at most in his dwelling and in dressing-up, etc.; and in his human functions he no longer feels himself to be anything but an animal. What is animal becomes human and what is human becomes animal.

In other words capitalism is not natural, and the artificial limits imposed on human development by our current forms of social organization prevent the vast majority of human beings from realizing their potential.

SO HOW does this relate to morality? Marx’s view of morality is a lot closer to the views of the ancient Greeks, particularly Aristotle, than it is to modern philosophers like Kant. Rather than thinking of morality as a set of rules to hold human nature in check, he sees morality as being about how human nature can flourish—how people can fully develop their capacities.

However, there is a twist.

For the past 10,000 years or so, human society has been divided into antagonistic classes, and that has meant that morality has developed not as a general theory of human emancipation, but as a set of rules by which each class attempts to further its own interests.

Marx points out the way in which these different class moralities come into conflict in capitalism:

The capitalist maintains his rights as a purchaser when he tries to make the working-day as long as possible, and to make, whenever possible, two working-days out of one. On the other hand, the peculiar nature of the commodity sold implies a limit to its consumption by the purchaser, and the laborer maintains his right as seller when he wishes to reduce the working day to one of definite normal duration. There is here, therefore, an antinomy, right against right, both equally bearing the seal of the law of exchanges. Between equal rights force decides. Hence is it that in the history of capitalist production, the determination of what is a working day, presents itself as the result of a struggle, a struggle between collective capital, i.e., the class of capitalists, and collective labor, i.e., the working-class.

But it does not follow that each of these moralities, the morality of the capitalists and the morality of the working class, is equally valid. For Marx argues that under capitalism, the working class is a universal class. In pursuing its own interests, the working class comes to represent the general interests of all humanity. Because it is in its interests to overthrow capitalism by emancipating itself, it will at the same time emancipate the whole of humanity.

In the struggle to end exploitation and oppression, workers will have to challenge the morality of the ruling class. When workers occupy a factory or homeowners refuse to leave a foreclosed property, capitalist morality is challenged. At a higher stage of the struggle it may be necessary to use force against the violence deployed by the state.

As the British Marxist Chris Harman explained it,

Marx saw that what is of cardinal importance is not the personal behaviour of the individual but the struggle between social forces, not personal morality but the fight to establish the good society. And in that struggle, the language of moralism was all too often the language used by the ruling class in order to constrain those who opposed it…. By contrast, every real development of working class struggle does begin to throw up the sort of values that point to the possibility of a truly cooperative and therefore truly human society. As against the atomization of the market, such struggles raise notions of solidarity, of mutual support, of a pooling of abilities, of cooperative endeavor.

Working-class morality is based on the goal of ending exploitation and oppression, but this in turn means not all actions can be justified. “The great revolutionary end,” wrote Leon Trotksy, “spurns those base means and ways which set one part of the working class against other parts…or lowers the faith of the masses in themselves and their organization.”

So while Marxism sees a basis for morality in shared human nature, while society is divided into classes, there can be no universal morality. Nevertheless, by fighting for its own interests, the working class makes it possible for such a morality to emerge. As Engels put it: