enlighten vs stir up

enlighten

verb
  • To make something clear to (someone); to give knowledge or understanding to. 

  • To supply with light. 

stir up

verb
  • To arouse or excite (passion or action). 

  • To move or disturb slightly; to make turbid. 

  • To mix (ingredients) by stirring. 

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