introspection vs reconnaissance

introspection

noun
  • A looking inward; specifically, the act or process of self-examination, or inspection of one's own thoughts and feelings; the cognition which the mind has of its own acts and states 

reconnaissance

noun
  • The act of scouting or exploring (especially military or medical) to gain information. 

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