callous vs warm-hearted

callous

adj
  • Having calluses, or relating to calluses. 

  • Emotionally hardened; unfeeling and indifferent to the suffering/feelings of others. 

warm-hearted

adj
  • kind, sympathetic and generous 

  • amicable and friendly 

How often have the words callous and warm-hearted occurred in a corpus of books? (source: Google Ngram Viewer )