Radical Reformation, a collective term for all those groups of
religious innovators of the 16th century on the European
continent who were neither Lutherans, nor Zwinglians, nor
Calvinists. Occasionally all these groups are broadly conceived
as the "Fourth Reformation." No doubt the Protestant revolt
against Rome opened the floodgates for all forms of separatism
which continued what is often called "medieval sectarianism." In
German official church history it has become customary to call
all those who opposed the Lutheran Reformation Schwärmer
(Enthusiasts) or Ketzer (hence Ketzerhistorie), a derogatory
term which did grave injustice to all dissidents. In the 20th
century the conceptions have changed somewhat under the impact
of the new science of sociology of religion. Now these groups
are often simply distinguished as "sects" in contrast to
"church" (Kirche), i.e., state church. Ernst Troeltsch was a
leader in this reclassification. In America the church
historians, having no use for these typically contine