Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Heresies and Heretics: Reference Books

In Catholicism, heresy is a controversial or unorthodox theological challenge that conflicts with scripture, Church Tradition, dogma, or doctrine.

Quick Ready Reference

Primary Sources


Digital Library of the Catholic Reformation


These Dictionaries and Encyclopedias can be quite useful for beginning research about Church History or Catholicism, or for clarifying terms and gaining background knowledge.  Many entries include bibliographies.

Broad-based Encyclopedias