illumination vs incentive

illumination

noun
  • Enlightening influence; inspiration. 

  • Adornment of books and manuscripts with colored illustrations. See illuminate (transitive verb). 

  • Festive decoration of houses or buildings with lights. 

  • The act of illuminating, or supplying with light; the state of being illuminated. 

  • Splendour; brightness. 

incentive

noun
  • Something that motivates, rouses, or encourages. 

  • A bonus or reward, often monetary, to work harder. 

adj
  • Inciting; encouraging or moving; rousing to action; stimulating. 

  • Serving to kindle or set on fire. 

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