IN SURVEYING the historical development of a certain period of human achievement, one tries to understand how events came to pass, what their causes were, and what the forces were that caused them to take place in a particular manner. In doing so, great difficulties are soon encountered because of the multitude and complexity of the circumstances at work. At first, one focuses all attention on the outstanding personalities, the heroes of history, as the great movers and agitators, only to find after a more careful survey that they, on their part, were also subjected to the forces brought to play upon them by the thoughts and acts of their contemporaries. This Tolstoian idea occurred to me soon after I had become preoccupied with the history of German dermatology, and it became the leading motif of this review.
At the beginning of the 19th century, we