Harnack, Adolf. “Excurs: Die Διδαχή und die Waldenser.” pp. 269-274. Lehre der Zwölf Apostel. Leipzig, J.C. Hinrichs, 1884.
Harnack observes that the conditions of society and the church naturally changed over time (Harnack 1884, 269). He particularly notes the greater institutionalization and organizational structure as limitations on the preaching and teaching. However, from the 3rd until the 15th century, there were moves to restore some sort of apostolic order. For this reason, it is interesting to consult a church order as old as the Didache, which was apparently not used a great deay beyond the 4th century, to evaluate later reform movements. Harnack consulted with an archivist in Munster, Dr. Keller, about a not-yet-released book entitled The Reformation and the Older Religious Parties (Harnack 1884, 270). Harnack finds that the Waldensian reform movement, in attempting to return to early Christian practices, did not create a system very similar to that described in the Didache. They met from house to house, relatively secretly, and pooled their resources so as to provide the best to their teachers. These habits were really not what the Didache describes from the early Christian period. The structure of the divine service is very different (Harnack 1884, 271). They also adopted a different view of bishops and deacons (Harnack 1884, 272).
Harnack considers that a pro-Catholic or anti-Catholic bias may influence reform movements, which react to their biases rather than to actual evidence of historic doctrine or practice, including a fair reading of the New Testament. The Waldensians specifically seem to have been influenced by the Baptist sects of their time (Harnack 1884, 274). The enthusiasm of the prophets, the anticlerical sentiments, and the desire for a vigorous Christianity all fit with that movement but do not necessarily reflect the earliest Chrsitians, who would not be reacting against a supposed less emotive and more hierarchical structure.