ethics vs rectitude

ethics

noun
  • Morality. 

  • The study of principles relating to right and wrong conduct. 

  • The standards that govern the conduct of a person, especially a member of a profession. 

rectitude

noun
  • Conformity to the rules prescribed for moral conduct; (moral) uprightness, virtue. 

  • Straightness; the state or quality of having a constant direction and not being crooked or bent. 

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