indifference vs sincerity

indifference

noun
  • Unbiased impartiality. 

  • Unconcerned nonchalance. 

  • The state of being indifferent. 

  • Unemotional apathy. 

  • Self-identity defined through the negation of difference, non-difference. 

  • A lack of enthusiasm. 

sincerity

noun
  • The quality or state of being sincere 

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