discourse vs rhetoric

discourse

noun
  • Expression in words, either speech or writing. 

  • A formal lengthy exposition of some subject, either spoken or written. 

  • An institutionalized way of thinking, a social boundary defining what can be said about a specific topic (after Michel Foucault). 

  • Any rational expression, reason. 

verb
  • To exercise reason; to employ the mind in judging and inferring; to reason. 

  • To engage in discussion or conversation; to converse. 

  • To write or speak formally and at length. 

rhetoric

noun
  • The art of using language, especially public speaking, as a means to persuade. 

  • Meaningless language with an exaggerated style intended to impress. 

adj
  • Synonym of rhetorical. 

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