Are mass ­murderers such as nurse Lucy Letby or those who carry out atrocities on a grander scale, such as war, simply evil? There is a tendency to present horrific, ­shocking acts as beyond comprehension. 

These acts have no ­explanation, it’s said, other than that a dark cloud of evil somehow descends over individuals or whole areas of the globe.  This supposed evil moves from serial killers to ­war-torn countries and ­genocidal violence.

While the tendency not to look at horror too closely is understandable, there are strong reasons to attempt analysis.

If we want to say Never Again to the Holocaust, for example, that means ­attempting to understand why it happened. Simply dismissing horrific acts as the result of some vague “evil” disguises the real ways that the system encourages and legitimises them. It lets the system off the hook.

Importantly, this is not for Marxists an attempt to explain fully every individual action or to draw meaning from them. 

Why a murderer carried out this act this way on this day is the stock and trade of salacious documentaries on perpetrators and serious memoirs and ­studies of victims.

The Russian revolutionary Leon Trotsky wrote, “Marxism can be applied with very great success even to the history of chess. But it is not possible to learn to play chess in a Marxist way.” This is not a pitch for CSI Marxism.

We cannot explain the ­precise interplay of causes, circumstances and choices that push one person to carry out a specific act. But we can provide context.

Marx said that human beings “make their own history, but they do not make it as they please—they do not make it under self-selected circumstances, but under circumstances existing already, given and transmitted from the past”.

Marx’s insight, despite the gender-specific language, was to point out that people interact and shape the world around them. But also that individuals cannot exert their will independently of the conditions in which they find themselves.

The first serious study of individual mass murderers in the 1980s by sociologist Elliot Leyton argued, “These people aren’t geniuses—they are evil, angry morons.” But he also went on to attempt to offer a theory that people defending class positions under threat produced multiple murderers.

The feudal era was rife with mass killings that were a product of a violently unequal system where lords and kings lived off the labour of the ­peasant class.

They asserted their ­domination through killing in periods of revolt.  These conditions ­produced aristocratic mass murderers, who preyed on peasants as victims. One of Leyton’s ­examples is the 15th century French Baron Gilles de Rais. 

He “murdered somewhere between 141 and 800 peasant children and was a ­personalised expression of the sweeping repressive thrust of his class”.

Moving on to the industrial periods Leyton argued that, “Middle class functionaries—doctors, teachers, professors, civil servants, who belonged to the class created to serve the needs of the new triumphant bourgeoisie—preyed on members of the lower orders, especially ­prostitutes and housemaids.”

Now this doesn’t explain ­everything, and there are holes in the history. 

Leyton underestimated the way in which, in modern times, an unstable working class ­produced murderers who have, more often than not, killed the oppressed and the weak. As Trotsky pointed out, who is weaker than a child? 

But compared to the media and legal approach of treating people as either “mad,” “bad,” or both, it points to the ­beginning of wisdom.

Far from being naturally adapted to capitalism, most humans are battered or broken by it. If the system doesn’t straight out kill them, it stunts their physical and mental development.  Their intellects are neglected, their artistic talents remain undiscovered or unappreciated. 

And the distinctively human capacity to engage in creative, socially useful work is reduced to a commodity worth only as much as the capitalist will pay for. 

We are drowning in what Marx called “the muck of ages”—racism, sexism, homophobia, competitiveness, conformity, passivity, insecurity—all the ideas capitalists require to divide and weaken the masses and maintain their minority hold on power.

We are reduced to passively watching the decisions or the performances of our “betters”.  Ordinary people are taught to believe we cannot be the agents of change in our own lives. 

We are bombarded with the idea that society and, indeed, history is made by great individuals, usually white men. And so “failure” is said to result from poor individual choices or worse because it is natural.

But for instance sexual ­violence isn’t a result of men being naturally misogynistic but because we live in a world that treats women as commodities and second-class citizens, while sexuality is alienated.

Economic crisis, oppression, poverty and unemployment are features of capitalist society that no individual on their own can alter.

There are ­multiple effects of living in a society based on violence and theft and how that shapes the individuals’ views about themselves, not to mention how they handle conflict and disappointment.

As Trotsky wrote, “Similar (of course, far from identical) irritations in similar conditions call out similar reflexes—the more powerful the irritation, the sooner it overcomes ­personal peculiarities.

“To a tickle, people react ­differently, but to a red-hot iron, alike. As a steam-hammer ­converts a sphere and a cube alike into sheet metal, so under the blow of too great and inexorable events, resistances are smashed and the boundaries of ‘individuality’ lost.”

Now the anger, exploitation and alienation within society result in strife for people. This manifests itself in a variety of ways, not all of them positive. 

To attempt to explain bad things is not to justify them.  There are all sorts of ­divisions in society that can lead to one group dominating and ­oppressing another. 

Every army hopes to produce routine and bureaucratic killers. But the effort required shows it is not natural. What Hannah Arendt called the banality of evil is hardwired into the system.  The costs are the victims of war and often the effects afterwards on the soldiers themselves. 

That society produces some individuals who go down a similar route is unsurprising when the institutions set up to ­protect this system’s existence are structured around maximising and normalising death and destruction.

Along with the hypocrisy of ruling ideas of what constitutes evil, we also have a set of rules on what it is to be “good”.  Moral concepts are social products. They assert a view of how human beings should behave if society is to continue to function.

If we lived in a stable, fair society that provided clear benefits to all, what is “good” would be straightforward. 

In a socialist society, “good” would mean actions that benefit the collective.  But in class societies, ­contradictory notions of what is “good” develop because of ­contradictions and conflicts.

A class that fights to preserve an existing society has one set of notions about what is necessary to keep society going and attempts to impose on people the moral notions that correspond to this. 

It has to portray the values it propagates as the values necessary for society as a whole, what is good for itself as absolutely “good”. Christianity, for example, taught that people were born “wicked”. 

This justified both the power of the church to bring them salvation in the afterlife and the power of the state to keep them in order in this life.

And because ideas about “good” behaviour are shaped by what benefits the ruling class, these morals are often imposed on working class people while those at the top do as they like. 

By contrast, a class that feels its needs are not met, and presses for society to be changed on a different basis begins to advance different ­interpretations of moral notions.  That is why there was a shift in moral values as capitalism replaced feudalism.

With capitalism we have the stage of a mode of production that not merely rests on the exploitation of the majority but threatens the destruction of all and the planet with it. 

That means the same morals preserving an order that ­prevents society functioning ends up ­justifying repeated barbarism on a mass scale and reproducing it at a localised level.

This is “evil” by any criteria. In contrast the struggles of the exploited under this system throw up notions of solidarity, sharing and egalitarianism. 

These lay the basis for a way out, and that is at least a good thing.