cause vs purpose

cause

noun
  • The source of, or reason for, an event or action; that which produces or effects a result. 

  • Sufficient reason for a state, as of emotion. 

  • A goal, aim or principle, especially one which transcends purely selfish ends. 

  • A suit or action in court; any legal process by which a party endeavors to obtain his claim, or what he regards as his right; case; ground of action. 

verb
  • To actively produce as a result, by means of force or authority. 

  • To set off an event or action. 

purpose

noun
  • The end for which something is done, is made or exists. 

  • meaning for existing or doing something. 

  • Resolution; determination. 

  • Function, role. 

verb
  • To have or set as one's purpose or aim; resolve to accomplish; intend; plan. 

  • To have (an) intention, purpose, or design; to intend; to mean. 

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