callous vs courteous

callous

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

  • Having calluses, or relating to calluses. 

courteous

adj
  • Showing regard or thought for others; especially, displaying good manners or etiquette. 

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