orthodoxy vs theology

orthodoxy

noun
  • Conformity to established and accepted beliefs (usually of religions). 

  • Correctness in doctrine and belief. 

theology

noun
  • A particular belief within a religion. 

  • Synonym of religious studies 

  • Subjective marginal details. 

  • An organized method of interpreting spiritual works and beliefs into practical form. 

  • The study of God, a god, or gods; and of the truthfulness of religion in general. 

How often have the words orthodoxy and theology occurred in a corpus of books? (source: Google Ngram Viewer )