affirmation vs explanation

affirmation

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

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

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

explanation

noun
  • Something that explains, makes understandable. 

  • A resolution of disputed points pursuant to discussion; a mutual clarification of disputed points; reconciliation. 

  • The act or process of explaining. 

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