knowledge vs letters

knowledge

noun
  • Intellectual understanding; the state of appreciating truth or information. 

  • Sexual intimacy or intercourse (now usually in phrase carnal knowledge). 

  • The fact of knowing about something; general understanding or familiarity with a subject, place, situation etc. 

  • Justified true belief 

  • The total of what is known; all information and products of learning. 

  • The deep familiarity with certain routes and places of interest required by taxicab drivers working in London, England. 

  • Awareness of a particular fact or situation; a state of having been informed or made aware of something. 

  • Something that can be known; a branch of learning; a piece of information; a science. 

  • Familiarity or understanding of a particular skill, branch of learning etc. 

letters

noun
  • The liberal arts, humanities, learning (broad accumulated cultural knowledge). 

  • Literature (school subject). 

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