certainty vs disbelief

certainty

noun
  • An instance of being certain. 

  • The state of being certain. 

  • A fact or truth unquestionably established. 

disbelief

noun
  • Unpreparedness, unwillingness, or inability to believe that something is the case. 

  • Astonishment. 

  • The loss or abandonment of a belief; cessation of belief. 

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