One of the most important influences on the thinking of Adolf Hitler was Robert Koch--who presented his discovery of the bacterium that causes tuberculosis on March 24, 1882. This led to widespread adulation of Koch and the development of "bacteriology"—whose basic message was that each disease is caused by a specific pathogen. If one could identify and isolate the pathogenic organism for any given disease--and destroy it—the disease would be cured.

Subsequent to Germany's loss in the First World War, Hitler tried to explain what had happened. He concluded that his nation had been ill. Suffering from a disease. This is how he explained Germany's loss of the war and why Germans were suffering.

Hitler built upon Koch's thinking, theorizing that every disease has a single cause. What was the pathogenic organism that was the source of Germany's disease? It was "the Jew." He experienced this "discovery" as a revelation. Now he knew the cause of Germany's suffering. It was a disease caused by the Jewish virus or Jewish bacteria; pathogenic organisms within the body politic.

How to cure the disease from which Germany was suffering? Remove Jews from within the German body politic. Once the pathogenic organisms had been removed, Germany would recover. She could get back on her feet; her disease would be cured.

Germany declared war against the Soviet Union on June 22, 1941. 

On July 10, 1941, Hitler declared: 

• I feel I am like Robert Koch in politics. He discovered the bacillus and thereby ushered medical science onto new paths. I discovered the Jew as the bacillus and fermenting agent of all social decomposition.

Hitler, February 22, 1942:

• The discovery of the Jewish virus is one of the greatest revolutions that has taken place in the world. The battle in which we are engaged today is of the same sort as the battle waged by Pasteur and Koch. How many diseases have their origin in the Jewish virus! We shall regain our health only by eliminating the Jew.

The Nazi revolution, Hitler believed, was a medical revolution. He had discovered the "Jewish virus" as the source of Germany's problems and suffering. He set in motion the Final Solution--as a cure.

March 24, 1882: Robert Koch announced the Discovery of the Tubercle Bacillus—the cause of tuberculosis—to the Berlin Physiological Society.

Writing on the history of German medicine, Paul Weindling (1993) describes how bacteriologists became aligned with the state—through the use of military analogies. Koch described how "alien parasites" entered the body. Laboratory researchers were compared to soldiers: "Warriors against disease."

There was widespread adulation of Koch. Thousands of handkerchiefs on which his face was embroidered were sold. Just as the bacterium causing tuberculosis had been isolated, so it was hoped that the germs of mental illness, criminality and feeble-mindedness could also be located.