ardor vs vehemence

ardor

noun
  • Great warmth of feeling; fervor; passion. 

  • Intense heat. 

  • Spirit; enthusiasm; passion. 

vehemence

noun
  • Eagerness, fervor, excessive strong feeling. 

  • A wild or turbulent ferocity or fury. 

  • An intense concentration, force or power. 

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