In the waning days of 1655, Amsterdam’s venerable rabbi, Saul Levi Morteira, sat down to update a sermon for his congregation. It was a message he had delivered decades earlier, but so many things had transpired in the intervening years, it was ripe for updating. And now, more than ever, it was time for the congregation to be thankful.

The sermon discussed the four kinds of weeping shown by Joseph in the Torah. In order, they were the weeping of supplication, the weeping of compassion, the weeping of anguish and the weeping of joy. But now, after many eventful years experienced by the Portuguese Sephardic community in Amsterdam, he had more immediate examples to draw on as well.

“At this time, we experienced a third weeping, of joy. This is because of the great miracle of abundant deliverance by which God has saved us from the plague that prevailed in this city for six months. Yet among all the Jews, no one died except two infants; they were like the two perfect lambs, an atonement sacrifice for the entire community. This is while the number of dead each week was close to nine hundred! God in his mercy saved our household! Therefore, cry out in joy for Jacob, shout at the crossroads of the nations (Jer. 31:2). … Thus we have seen that thousands and myriads have fallen from our right side, but God has not afflicted us, He has saved our homes.”

Inescapable, unstoppable horror

We know an awful lot more about diseases and how they are spread now than they ever knew in the 1600s, starting with the fact that people then didn’t even have a handle on what the bubonic plague was. Some thought it was a divine judgment on communities that had strayed too far from the word of God. Other, more scholarly minds thought that “bad humors,” or fetid air, was to blame. Sometimes, more fanciful explanations like earthquakes or comets were blamed. No one had the scientific knowledge, much less the imagination, to guess that organisms so small they couldn’t be seen by the eye were spreading swift and sure death person to person, city to city, nation to nation.

In fact, it would take the invention of the Dutch, the microscope, and the obsessive work of Antony van Leeuwenhoek to even see bacteria for the first time. But even then, it would take until 1894 for Alexandre Yersin to pinpoint the particular bacteria to blame. At the same time, he also noted that the outbreak in Hong Kong that year coincided with a large number of dead rats in the streets. Four years later, Yersin’s partner, Paul-Louis Simond, realized that the rats were teeming with fleas, and that flea bites were present on plague victims.

The plague claimed up to 90 percent of its victims, depending on whether it presented as bubonic (swollen lymph nodes), pneumonic (in the lungs and spread by coughing) or septicemic (in the blood), with pneumonic cases the most deadly. But with the advent of antibiotics, the Black Death is nearly always treatable now if caught early enough. And that’s a good thing, because to this day, there are still cases of the plague reported annually around the world. Even this year (2019), a child contracted the plague in Idaho.

But in the 1600s, ignorant to what was causing the terrifying disease or what might stop it, people felt powerless. That didn’t stop them from trying.

Many with the means to do so fled the cities. Rabbi Morteira noted in his sermon that several Jews in the Portuguese congregation left Amsterdam during the plague of 1655. So many, in fact, that it put the many charities that the community depended on — charities that taught job skills to orphans, provided dowries to poor young women, care for the sick and elderly and resettle refugees — were struggling to get by.

At the height of the “Black Death” in the 1300s, people went a little bit nuts. They flaggilated themselves to make amends to God in an attempt to end the spreading disease and murdered Jews, who they figured must be to blame (why not?). Some gave in to licentiousness because they thought the world was coming to an end (why not?).

But by the 1600s, the Age of Reason was starting to take hold, just a little. This time, people were turning to medicine, at least as they understood medicine to be. Plague doctors, characterized by perhaps the creepiest uniform of all time — a man-sized crow-like monstrosity — did their best to contain the contagion.

Summer of Sorrow

But back to the summer months of 1655 in Amsterdam. The city was in the middle of its boom years. It had grown beyond belief from the small but hopeful trading town it had been in 1580, at the start of the Dutch Republic. Then, it was home to just about 30,000 people. By 1650, the population had exploded seven-fold to 210,000 people, many of them immigrants, like those from Portugal, but others from Germany, France, Sweden, England and other places as well.

That made Amsterdam crowded, as there was hardly time to build not only houses, but to dig canals and create suitable land to sustain habitation for the growing city. At the same time, a large volume of ships coming in and out of the harbor bearing not only goods but pathogens from around the globe. This created a welcome home for rats, and that set the stage for a plague outbreak.

It had happened here before. Another outbreak of plague coincided with the so-called Tulipmania of 1637, and according to some economists, may have been one of the reasons that tulip fever broke: traders simply became too afraid to gather at the taverns where the futures trading was done. And outbreaks would happen again after the outbreak of 1655. Notably, the outbreak of 1664 took 24,148 lives, more than the outbreak in 1655.

However, 1655 is the period I’m writing about in my novel, so bear with me.

When all was said in done in 1655, the plague took 16,727 lives, or 7.9 percent of all residents, which is a staggering amount to contemplate. While Morteira insists only two of the victims were Jews — baby girls, specifically — historian Steven Nadler finds this far-fetched. “There is no record of how many Jews were carried away by the epidemic, but it is reasonable to assume, once again, some proportionate contagion among them,” he wrote in his biography “Spinoza: A Life.”

The outbreak of plague started in the summer months. Perhaps it was a rat rushing off a ship that had docked in the harbor that did it, or a sailor come ashore who coughed in one of the taverns. There’s just no way of knowing. But once it started, the plague took hold and shook the city ferociously, and no one knew when it might end. Only when cold weather moved in, perhaps killing off some of the rats, the vector of the disease, did terror cease.

The end of this plague outbreak came less than a year from Spinoza’s expulsion from the Jewish community, so it’s entirely possible that he sat among the congregation as Rabbi Morteira delivered this sermon, declaring that the Jewish community had been spared at the expense of its gentile neighbors. It’s interesting to imagine what he might have made of that, and how that would have squared with his developing philosophy.

At any rate, we know how that story ends.