Aloys Alzheimer, a coworker of Emil Kraepelin.

In the last 10 years most people in the western world have become fully aware of the medical and social dimensions of Alzheimer's disease. One might conclude, therefore, that the life of Aloys Alzheimer (1864-1915) would be an object of intensive study. However, compared to other scientists from the turn of the century, our knowledge of Alzheimer is still limited. One of the most decisive factors in his life was Emil Kraepelin, the real "inventor" of the Alzheimer dementia. A critical-historical attitude should be especially maintained if one looks at Alzheimer's dementia, Alzheimer's famous "discovery". Many of today's psychiatrists would assume that the description of Alzheimer's disease was the scientific climax of Alzheimer's professional life and the ultimate aim of his research. However, this view is the result of our modern knowledge. Kraepelin's creation of Alzheimer's disease in 1909 was not based on a large number of "objective" findings, but on his idea of "nosological entities". Alzheimer's disease is a striking example of the fact that a new medical idea must comprise conceptual prerequisites, clinical observations and innovative technologies.