affirmation vs proving

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. 

proving

noun
  • Experimentation to determine which substances cause which effects when ingested. 

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