incitement vs motivation

incitement

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

motivation

noun
  • Willingness of action especially in behavior. 

  • Something which motivates. 

  • A research rating that measures how the rational and emotional elements of a commercial affect consumer intention to consider, visit, or buy something. 

  • The action of motivating. 

  • An incentive or reason for doing something. 

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