The same faith [of the High Middle Ages] was the common heritage of high and low alike, on the banks of the Danube, Rhine, or Rhone, or Thames…Christianity was included in the very definition of their citizenship…By heresy, they sinned against the citizenship in which all shared. The strength of this feeling goes a long way to explain that the first violence done against the heretics, the first lynchings, were the work not of the rulers, ecclesiastic or temporal, but of the common people – a spontaneous outburst against what outraged their deepest instincts. It was a symptom of the close interlocking of Church and State, whatever other factors were involved.
Maurice Bevenot, S.J. “The Inquisition and its Antecedents,” The Heythrop Journal (1966)