fallacy vs surety

fallacy

noun
  • An argument, or apparent argument, which professes to be decisive of the matter at issue, while in reality it is not; a specious argument. 

  • Deceptive or false appearance; that which misleads the eye or the mind. 

surety

noun
  • A promise to pay a sum of money in the event that another person fails to fulfill an obligation. 

  • One who undertakes to pay money or perform other acts in the event that his principal fails therein. 

  • A substitute; a hostage. 

  • Evidence; confirmation; warrant. 

  • Certainty. 

  • That which makes sure; that which confirms; ground of confidence or security. 

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