Perhaps the most important influence 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.

Hitler built upon Koch's theory. He believed that--subsequent to World War I--Germany was ill. The cause Germany's disease and her suffering was a pathogenic organism lying within the body politic. Hitler and his colleagues referred to Jews as a "disease within the body of the people."

The Holocaust was a response to this belief or perception, the purpose of which was to remove Jewish bacteria from within the German body politic. Hitler's primary objective as a political leader was to destroy Jewish bacteria; to save the world by making it "Jew free."

The genocide of the Jews grew out of this fantastic idea.

The Final Solution was based on a fantasy enacted in reality. This fantasy was governed by a logic (the logic that German was a body with an immune system). However, this logic grew out of an entirely irrational idea.  Germany was not a body and the Jews were not bacteria.

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, in Hitler's mind, was a medical revolution. He imagined that he had discovered the "Jewish virus" as the source of Germany's problems, indeed, as the source of the world's problems. He set in motion the Final Solution--to eliminate the source of the world's disease.

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: "Warrior 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.