Home » Health » Microbes have played a key role in human history, including the potato famine in Ireland caused by Phytophthora infestans, which led to typhus epidemics and a diaspora. Kennedy’s book, Pathogenesis, examines the impact of infectious diseases on history, with an emphasis on Marxist views of conflict between social groups. He suggests that COVID-19 will be a turning point in history, but the author disagrees, noting that previous pandemics have had similar effects. Kennedy’s book is well-written and controversial, focusing on the history and sociology of pandemics rather than their science.

Microbes have played a key role in human history, including the potato famine in Ireland caused by Phytophthora infestans, which led to typhus epidemics and a diaspora. Kennedy’s book, Pathogenesis, examines the impact of infectious diseases on history, with an emphasis on Marxist views of conflict between social groups. He suggests that COVID-19 will be a turning point in history, but the author disagrees, noting that previous pandemics have had similar effects. Kennedy’s book is well-written and controversial, focusing on the history and sociology of pandemics rather than their science.

The Black Death was undoubtedly one of the deadliest pandemics in human history, claiming millions of lives across Europe in the mid-14th century. Its impact on society and the economy was significant, leading many to believe it was a turning point in history that marked the end of feudalism and the birth of capitalism. However, the debate surrounding the Black Death’s role in shaping socio-economic conditions is far from settled, with many scholars offering conflicting views on whether it was the disease that broke feudalism and ushered in capitalism, or whether it simply accelerated preexisting trends. In this article, we will explore the arguments on both sides of this debate and examine the lasting legacy of the Black Death on European society and economy.


In his book “Pathogenesis: How Germs Made History”, Jonathan Kennedy explores the role of microorganisms in shaping human history. One such example is the Great Famine that occurred in Ireland during the 1840s, caused by the potato pathogen Phytophthora infestans. Between 1845 and 1852, the famine led to crop failures, which resulted in the death of an estimated one million people due to typhus (caused by Rickettsia prowazekii bacteria) and relapsing fever. The famine had a lasting impact on Ireland and played a significant role in the country’s diaspora.

Kennedy approaches his examination of microbes and their effects on human history from a Marxist view of history, where social conflict between groups is the main driver of change. He explores how prehistoric and medieval events, along with slavery, colonialism, and the Industrial Revolution, may be linked to the spread of infectious diseases, ultimately culminating in the current COVID-19 pandemic.

While Kennedy’s book covers many well-known pandemics and plague outbreaks, it ignores many crucial human pathogens that operate differently, such as Mycobacterium tuberculosis and hookworm. The reduction in tuberculosis in the United Kingdom could be attributed to various factors, including improved public health regulations and the increased availability of affordable protein-rich foods. Similarly, housing improvements, including properly draining toilets, have played a significant role in decreasing hookworm infection rates.

Although Kennedy’s book is well written, it does not delve into the science of pandemics in great detail. Instead, it offers a unique perspective on the history and sociology of pandemics, highlighting their lasting impact on human societies. Whether COVID-19 will have a similar impact remains uncertain, but its response worldwide has been unprecedented, from the implementation of lockdowns to the genomic definition of its progress.

Overall, Kennedy’s book provides a fascinating perspective on the role of microorganisms in shaping human history, encouraging readers to consider the far-reaching impact of infectious diseases.


In conclusion, while the Black Death did have significant effects on medieval Europe, including the breakdown of feudalism and the rise of capitalism, it is important to note that these changes did not happen overnight. Rather, they were gradual processes that unfolded over several centuries, with multiple factors at play. While it is tempting to attribute these changes solely to the Black Death, it is important to consider the many other economic, social, and political factors that were in play during this period. Ultimately, the story of the Black Death and its aftermath is a nuanced and complex one, and one that continues to inspire debate and discussion among historians today.

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