The doctor who carried out the study claims that the universally accepted story of Nietzsche having caught syphilis from prostitutes was concocted after World War II by Wilhelm Lange-Eichbaum, an academic who was one of Nietzsche's most vociferous critics. It was then adopted as fact by intellectuals who were keen to demolish the reputation of Nietzsche, whose idea of a "superman" was used to underpin Nazism.

The new research was done by Leonard Sax, the director of the Montgomery Centre for Research in Child Development in the United States. Dr Sax studied accounts of Nietzsche's collapse with dementia in 1889, when he was admitted to an asylum in Switzerland and initially diagnosed as being in the advanced stages of syphilis.

According to Dr Sax, however, Nietzsche's notes show no signs of the symptoms now regarded as evidence of this disease, such as an expressionless face and slurred speech.

