free speech vs liberation

free speech

noun
  • Expressions that are or should be allowed in some moral or legal context. 

  • The right to express an opinion in public without being restrained or censored. 

liberation

noun
  • The act of liberating or the state of being liberated. 

  • The achievement of equal rights and status. 

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