apathy vs ardor

apathy

noun
  • Lack of emotion or motivation; lack of interest or enthusiasm towards something; disinterest (in something). 

ardor

noun
  • Intense heat. 

  • Great warmth of feeling; fervor; passion. 

  • Spirit; enthusiasm; passion. 

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