consent vs sanction

consent

verb
  • To express willingness, to give permission. 

  • To cause to sign a consent form. 

  • To agree in opinion or sentiment; to be of the same mind; to accord; to concur. 

noun
  • Voluntary agreement or permission. 

sanction

verb
  • To give official authorization or approval to; to countenance. 

  • To penalize (a state etc.) with sanctions. 

  • To ratify; to make valid. 

noun
  • An approval, by an authority, generally one that makes something valid. 

  • A penalty, punishment, or some coercive measure, intended to ensure compliance; especially one adopted by several nations, or by an international body. 

  • A law, treaty, or contract, or a clause within a law, treaty, or contract, specifying any of the above. 

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