denialism vs gainsaying

denialism

noun
  • The practice of rejecting propositions which are strongly supported by scientific or historical evidence, and often of seeking to influence policy processes and outcomes accordingly. 

gainsaying

noun
  • Refusal to accept or believe something. 

  • Denial; denying. 

  • Rebellious opposition; rebellion. 

  • Contradiction. 

  • Opposition, especially in speech. 

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