affirmation vs contention

affirmation

noun
  • A form of self-forced meditation or repetition; autosuggestion. 

  • That which is affirmed; a declaration that something is true. 

  • The solemn declaration made by Quakers and others incapable of taking an oath. 

contention

noun
  • A point maintained in an argument, or a line of argument taken in its support; the subject matter of discussion of strife; a position taken or contended for. 

  • Competition by parts of a system or its users for a limited resource. 

  • Argument, contest, debate, strife, struggle. 

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