incitement vs rationale

incitement

noun
  • A call to act; encouragement to act, often in an illegal fashion. 

rationale

noun
  • A justification or rationalization for something. 

  • An explanation of the basis or fundamental reasons for something. 

  • A liturgical vestment worn by some Christian bishops of various denominations. 

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