Why Historical Material?

Written historical sources reflect the centuries-long development of medical
traditions and continuous choice of which treatments were perceived as truly effective and which were not.

Medieval doctors had such traditions at their disposal, which made their treatments and base of knowledge richer and more diverse.

The possibility of using written material makes it possible for one person to
cover immensely more material than an ethnographic field worker, and to
extract the common medical denominators across the various authors and
texts representing the cumulative experience of many people.

The effects of a treatment have been tested in humans and results observed
over a period of several generations.