humane vs relentless

humane

adj
  • Pertaining to branches of learning concerned with human affairs or the humanities, especially classical literature or rhetoric. 

  • Having or showing concern for the pain or suffering of another; compassionate. 

relentless

adj
  • Unrelenting or unyielding in severity. 

  • Unremitting, steady and persistent. 

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