conscience vs credo

conscience

noun
  • A personification of the moral sense of right and wrong, usually in the form of a person, a being or merely a voice that gives moral lessons and advices. 

  • The moral sense of right and wrong, chiefly as it affects a person’s own behaviour and forms their attitude to their past actions. 

credo

noun
  • A statement of a belief or a summary statement of a whole belief system; also (metonymically) the belief or belief system itself. 

  • The liturgical creed (usually the Nicene Creed), or a musical arrangement of it for use in church services. 

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