free-thinking vs irreligious

free-thinking

adj
  • Having opinions that are contrary to dogma or the positions of authority. 

irreligious

adj
  • Contrary to religious beliefs and practices. 

  • In conscious rejection of religion. 

  • Having no relation to religion. 

How often have the words free-thinking and irreligious occurred in a corpus of books? (source: Google Ngram Viewer )