Robert Willan and the French Willanists.

In 1798, Robert Willan published the founding textbook of British dermatology. In adopting the elementary lesions principle previously described by Josef Plenck and improving the nomenclature of the skin diseases, Willan established a method for the diagnosis and a doctrine for the nosology of the cutaneous diseases. Introduced into France by Biett in the 1810s, the Willanist method, which allowed diagnosis on the basis of objective criteria, was adopted by the majority of the dermatological community. However, as a doctrine, Willanism, the use of elementary lesions as a framework for classifying diseases, became the subject of lasting debate. In fact, apart from a few, most leading French dermatologists did not accept Willan's doctrine and preferred classifications according to systems which were supposed to reflect the best understanding of the cutaneous diseases: physiological, aetiological and pathological. Willanism is still used by every dermatologist as a method for recognizing skin diseases. It constitutes a firm link to the founding period of modern dermatology and remains a bastion against uncertain hypotheses.