certainty vs vacillation

certainty

noun
  • The state of being certain. 

  • A fact or truth unquestionably established. 

  • An instance of being certain. 

vacillation

noun
  • Changing location by moving back and forth. 

  • Indecision in speech or action. 

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