The physician U. G. Bucher was a student of Friedrich Hoffmann who together with Boerhave in
Leiden and Stahl in Halle was one of the three major theoreticians of medicine in the early
18th century. The 'Brief-Wechsel' (Correspondence) presumably written by Bucher is the most
important contribution of German freethinking to the criticism of spiritualist rational
psychology. The standpoint expressed in the 'Brief-Wechsel' is a materialism which originated
from medical and philosophical sources (Hobbes among others) on the basis of which a
sensualistic epistemology is outlined.
