Human Progress: (2) Life is Healthier

Good health is a precondition for a good life.  If we are crushed by disease, injury, or undernourishment, we cannot live a happy and flourishing life.  Throughout most of human history, most human beings were disabled in their lives or died prematurely from poor health.  Although this is still true today for many people around the world, over the past two hundred years, human life has become healthier on average than it ever was before 1800.  This has been caused by the increasing freedom, knowledge, and technology coming from the Liberal Enlightenment. (See Max Roser's survey of the data for "Global Health.")

One reminder of the catastrophic effects of epidemic diseases in human history is Thucydides' account of the plague in Athens during the Peloponnesian War.

The Peloponnesian War between Athens and Sparta and their allied cities began in the summer of 431 BCE. Athens was led politically and militarily by Pericles. In the winter of 431, he delivered the Funeral Oration for those Athenians who died in the first year of the war. As reported by Thucydides, in his history of the war, Pericles' speech was a celebration of the power and the virtues of the Athenians as shaped by the freedom they enjoyed in their democracy. 

As I have indicated in a previous post, ancient Athens manifested some of the economic, social, and political success of the Liberal Enlightenment, although it did not achieve the uniquely self-sustained and accelerating growth of the Great Enrichment in northwestern Europe and North America at the end of the 19th century.

In the first days of summer in 430 BCE, the Spartans and their allies invaded Attica once again, initiating the second year of the war.  But Thucydides passes over this quickly in one sentence, so that he can turn immediately to a careful and dramatic description of the plague that began to appear in Athens that summer (2.47-58). It is a jolting effect for readers to have Pericles' beautiful funeral speech followed by an ugly account of a plague where bodies were left unburied.  Readers might see that the implied question here is the human meaning of death: death in war can be glorious, but death in a plague is not.

The plague killed Pericles, and for that reason alone it might have turned the course of the war against Athens.  Thucydides himself had the disease, but he was one of the lucky ones who recovered, which gave him immunity and allowed him to study the disease in others. 

His scientific attitude in his careful observation and recording of the disease might show the influence of Hippocrates, who stressed the importance of recording clinical histories of diseases and of looking for natural causes rather than superstitiously assuming that there are divine causes.  Hippocratic medical science was limited, however, by the ancient Greek taboo against the dissection and autopsy of human bodies, so that their inferences about human anatomy came from the dissection of other animals.  It was also limited by the absence of microscopes for seeing microorganisms, so that the bacterial and viral causes of disease were invisible.

Thucydides says that physicians were completely ignorant of the causes of the disease, and they knew no way to treat it. In fact, the physicians commonly died from the disease because they had contact with the sick.  Not only did all human arts fail to stop or slow the disease, even supplications in the temples of the gods and divinations failed, and eventually people stopped appealing to the gods.

Thucydides traces the path of the plague from sub-Saharan Africa to Egypt and Libya and then through Persia to Athens.  Leaving to others any speculations about the causes of the disease, he proposes only to lay out the symptoms of the disease so that it can be recognized if it ever breaks out again.

The mortality rate was high, and victims generally died on the seventh or eighth day after first contracting the disease.  But those who survived were protected from reinfection.

People in good health suddenly felt headaches, and they had inflammation and redness of the eyes, bleeding from the mouth, small pustules and ulcers over the body, vomiting, diarrhea, stomach pain, violent spasms, and unquenchable thirst.  They were never able to rest or sleep. Many lost their fingers, their toes, and their genitals from the violent swelling and ulceration.  Some lost their memory, so that even if they survived, they did not know themselves or their friends.

People died alone, because their family and friends were afraid to care for them, for fear of contracting the disease.  Those few who were good enough to care for the victims often died as a result.  The most caring and compassionate people were those who had recovered from the disease, and so they knew that they could care for the sick without fear of being attacked by the disease.

Bodies were thrown into piles to be burned without ceremony.  Many bodies laid unburied.

When the sick thought they were dying, they became utterly lawless, because since they saw themselves as already under a sentence of death, they had no fear of either human law or divine law.  They ceased worshipping the gods, because they saw no benefit in this.

Some people thought this plague was the fulfillment of ancient prophecies and oracles foreseeing that such a pestilence would be inflicted on the Athenians to give victory to the Spartans.  But Thucydides was skeptical about this.

Thucydides says that the plague was "too much for human nature to endure" and "stronger than reason" or "beyond rational explanation" (kreisson logou).

The dark pessimistic mood of this description of the plague in Athens was recreated by Lucretius at end of his De Rerum Natura, where he recounted the story of the Athenian plague as told by Thucydides.  Many readers have found it strange that Lucretius chose to end his book this way, with a sad rather than a happy ending, because the argument of the book is that the Epicurean philosophic teaching allows us to avoid any fear of death that would ruin our happiness in life.  It is odd, then, that Lucretius does not suggest that Epicurus or an Epicurean would have withstood the horrible circumstances of the plague any better than anyone else. 

Lucretius presents the plague at the end of his book as if it were the end of the world caused by natural causes.  As I have indicated in previous posts (with links here), Lucretius taught that since the cosmos was not designed by providential gods who care for human beings, the cosmic conditions necessary for human life are not eternal, and thus the human world must someday come to an end, and human life on Earth will be extinguished. For Leo Strauss and the Straussians, this is "the most terrible truth."

While Thucydides had no rational explanation for the plague, modern historians and scientists have offered a wide variety of explanations for it as epidemic typhus, anthrax, typhoid fever, bubonic plague, smallpox, measles, or toxic shock syndrome.  Most recently, some researchers have argued that the clinical and epidemiologic features of the disease as described by Thucydides conform best to Ebola, which was first recognized in humans in 1976, and which appeared recently in an outbreak in sub-Saharan Africa in 2014-2016. (See Powel Kazanjian, "Ebola in Antiquity?", Clinical Infectious Diseases 61 [2015]: 963-68.)  Ebola is a deadly virus disease that kills about 50% of the people that suffer from it.  The ancient Greeks could not have understood such a disease since the virus cannot be seen with the naked eye. But while modern science can explain the disease, there is so far no known cure.  Understanding the disease and how it spreads through contact with bodily fluids does at least allow for containing it, and the recent epidemic was brought under control by the spring of this year.

Other epidemic diseases that have ravaged human life throughout history have been brought under control or even largely eliminated through modern scientific technology. For example, the bubonic plague is now understood as caused by the bacterium Yersinia pestis, which is transmitted by fleas carried by rodents.  Originating in China, the bubonic plague was responsible for three long-lasting epidemics in Europe: the Justinian Plague (the 6th through the 8th centuries), the Black Plague (from the mid-14th century to the Great Plague of London in 1665), and the third pandemic at the end of the 19th century.  The Black Plague killed 30%-60% of Europe's total population.  Although it could still become a major health threat, the bubonic plague has been controlled by insecticides, antibiotics, and a plague vaccine.  Other epidemic diseases that have claimed hundreds of millions of lives over human history have been almost completely eradicated--such as smallpox and malaria.

The Liberal Enlightenment has promoted the knowledge and the technology that has made this human progress in health possible.  It has also promoted the statistical knowledge that makes it possible to precisely measure this progress.

As Max Roser indicates in his article on the "Burden of Disease," the Global Burden of Disease Project (GBD) of the Institute for Health Metrics and Evaluation measures the Disability Adjusted Life Years (DALYs) lost per 100,000 people.  This is the sum of years of potential human life and flourishing lost due to premature mortality and the years of productive life lost due to disability. 

So, for example, the DALYs for Ebola in 2015 were zero for almost all nations, but they were 2,734.33 for Sierra Leone, 1,424.39 for Liberia, and 432.91 for Guinea.  The reduction in the damage from typhoid fever over the past 25 years can be measured by the DALYs for this disease.  In 1990, the DALYs for India were 928.45 and for Burkina Faso 1,232.25.  In 2015, the DALYs were 436.68 for India and 587.97 for Burkina Faso.  The DALYs for the United States, Great Britain, and many other countries were almost zero.