I’ve written a biography of Luther, but until the Covid-19 pandemic I had never thought deeply about the impact of plague on him. I had assumed plague was something early modern people took in their stride, and its history the territory of specialist medical historians. Having been in solitary quarantine in Australia, I now realise how wrong I was.

Plague struck Wittenberg in August 1527, ten years after Luther posted – or didn’t post; historians disagree – the 95 Theses on the door of the castle church, and two years after the Peasants’ War of 1525, when thousands of peasants were slain after they revolted against their lords. Luther had backed the authorities in putting down the revolt with massive bloodshed. Earlier in 1527, Luther had undergone a major physical and emotional collapse, and found himself unable to write or read for some months. Then, just as he was starting to recover, plague broke out in the town.

That dreadful late summer and autumn in Wittenberg, Luther and his family, the town pastor Johannes Bugenhagen and two chaplains stayed behind when many fled for safety: Philip Melanchthon, one of Luther’s closest collaborators, did not stay. I can now imagine the eeriness of the deserted and silent town, and Luther’s anxiety about whether the university would ever re-open. They appreciated, as we have had to learn, that economic exchange, friendships, social life, can suddenly be undone by disease.

Luther wrote a remarkable pamphlet, Whether One May Flee from a Deadly Plague, which advocates social distancing and says that the worst people are those who, knowing they are sick, deliberately go out and infect others. Luther is in no doubt that pastors have a moral duty to stay and care for their congregations like a ‘good shepherd’. Only if there are enough clergy is it all right to leave. The same is true of civil servants: government must continue to function. Luther doesn’t mention physicians or surgeons, but advocates building hospitals. He speaks warmly of nursing and its importance. Everyone, he insists, must help their neighbour; nursing is a duty for all, men as well as women.

Pastors have to help the dying, he says, because ‘when people are dying, they most need a spiritual ministry which strengthens and comforts their consciences by word and sacrament and in faith overcomes death.’ This struck me with particular force, because it is not happening now, as people die without friends and family around them. Luther confronted this issue head on, with the risk of infection to himself and his pregnant wife and child. He held the wife of the mayor in his arms as she was dying. The pregnant wife of his chaplain, Georg Roerer, caught the plague too: she managed to give birth but the baby was still-born, and then she too died of plague. Luther knew the costs of deciding to help the dying.

Luther sees plague as God’s punishment for sin, but his extreme Augustinianism meant that, since all humans are sinners and earning salvation is impossible, plague is just something to be accepted. One interesting consequence of this view is that there is no one to blame.

In one remarkable passage Luther points out that if Christ or the Virgin Mary were to suffer, everyone would rush to help – but Christ is in every stranger, and so we must help everyone, no matter how poor or repellent a plague victim is: ‘When anyone is overcome by horror and repugnance in the presence of a sick person he should take courage and strength in the firm assurance that it is the devil who stirs up such abhorrence, fear and loathing in his heart.’

In the final section, Luther insists that the worst plague is the people who insist on the spirit and deny the flesh. Here we see the other side of Luther, the man who took a dogmatic line in Reformation debates. He was obsessed with the Sacramentarians, his erstwhile followers who denied that Christ was truly present in the bread and wine at communion. He thought they were prompted by Satan and ‘like a bedbug which itself has a foul smell, but the harder you rub to crush it, the more it stinks’. He promises, if God allows him time, to write yet again against the Sacramentarians. His intransigence on the issue split the Reformation. The real presence of Christ in the eucharist was key to his theology, and he had no respect for those who took a different view. It meant that the Protestants could never unite, but he couldn’t reach a compromise with the Catholics either. The result was a century of conflict.

Luther saw all this as a cosmic struggle between God and the Devil; the Devil makes the ill person repugnant to us, makes us reluctant to help our neighbour because

the devil would excrete us out of this life as he tries to make us despair of God, become unwilling and unprepared to die, and, under the stormy and dark sky of fear and anxiety, make us forget and lose Christ … and desert our neighbour in his troubles.

(The German is earthier than ‘excrete’.) Luther’s recognition of mental states, depression in particular, is remarkable – especially as he was still recovering from it. More foreign is the way he projects his inner world onto something external, the Devil, viewing his emotional battle as a struggle between God and Satan. He comforted himself by conducting imaginary dialogues with the Devil: ‘Get away, you Devil, with your terrors!’ And it meant he could conceptualise his inadequacies, and those of others, without pretending they did not exist. But externalising and alienating your emotions comes at a cost, and it meant that his opponents, including his former supporters and closest associates, were treated as tools of Satan.

In a way not too different from Luther’s, we may also project our sufferings outward during the pandemic and regard Covid-19 as a ‘war’, a moral battlefront – an emotional discourse that distracts from the loss, pain and grief of the illness. But the crisis of lockdown and the suspension of our everyday social worlds also gives the chance to think creatively about what is most important and how we might do things differently.