callous vs penitent

callous

adj
  • Having calluses, or relating to calluses. 

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

penitent

adj
  • Feeling pain or sorrow on account of one's sins or offenses; feeling sincere guilt. 

  • Doing penance. 

noun
  • One under church censure, but admitted to penance; one undergoing penance. 

  • One under the direction of a confessor. 

  • One who repents of sin; one sorrowful on account of their transgressions. 

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